# TreeMap

public class **TreeMap** extends [AbstractMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractMap.html)\<K, V\>  
implements [NavigableMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html)\<K, V\> [Cloneable](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Cloneable.html) [Serializable](https://developers.google.com/j2objc/javadoc/jre/reference/java/io/Serializable.html) A Red-Black tree based `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html` implementation.
The map is sorted according to the {@linkplain Comparable natural
ordering} of its keys, or by a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Comparator.html` provided at map
creation time, depending on which constructor is used.

This implementation provides guaranteed log(n) time cost for the
`containsKey`, `get`, `put` and `remove`
operations. Algorithms are adaptations of those in Cormen, Leiserson, and
Rivest's *Introduction to Algorithms*.

Note that the ordering maintained by a tree map, like any sorted map, and
whether or not an explicit comparator is provided, must be *consistent
with `equals`* if this sorted map is to correctly implement the
`Map` interface. (See `Comparable` or `Comparator` for a
precise definition of *consistent with equals* .) This is so because
the `Map` interface is defined in terms of the `equals`
operation, but a sorted map performs all key comparisons using its `compareTo` (or `compare`) method, so two keys that are deemed equal by
this method are, from the standpoint of the sorted map, equal. The behavior
of a sorted map *is* well-defined even if its ordering is
inconsistent with `equals`; it just fails to obey the general contract
of the `Map` interface.

**Note that this implementation is not synchronized.**
If multiple threads access a map concurrently, and at least one of the
threads modifies the map structurally, it *must* be synchronized
externally. (A structural modification is any operation that adds or
deletes one or more mappings; merely changing the value associated
with an existing key is not a structural modification.) This is
typically accomplished by synchronizing on some object that naturally
encapsulates the map.
If no such object exists, the map should be "wrapped" using the
`https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collections.html#synchronizedSortedMap(java.util.SortedMap<K,%20V>)`
method. This is best done at creation time, to prevent accidental
unsynchronized access to the map:

```
   SortedMap m = Collections.synchronizedSortedMap(new TreeMap(...));
```

The iterators returned by the `iterator` method of the collections
returned by all of this class's "collection view methods" are
*fail-fast* : if the map is structurally modified at any time after
the iterator is created, in any way except through the iterator's own
`remove` method, the iterator will throw a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/ConcurrentModificationException.html`. Thus, in the face of concurrent
modification, the iterator fails quickly and cleanly, rather than risking
arbitrary, non-deterministic behavior at an undetermined time in the future.

Note that the fail-fast behavior of an iterator cannot be guaranteed
as it is, generally speaking, impossible to make any hard guarantees in the
presence of unsynchronized concurrent modification. Fail-fast iterators
throw `ConcurrentModificationException` on a best-effort basis.
Therefore, it would be wrong to write a program that depended on this
exception for its correctness: *the fail-fast behavior of iterators
should be used only to detect bugs.*

All `Map.Entry` pairs returned by methods in this class
and its views represent snapshots of mappings at the time they were
produced. They do **not** support the `Entry.setValue`
method. (Note however that it is possible to change mappings in the
associated map using `put`.)

This class is a member of the
[Java Collections Framework](https://developers.google.com/j2objc/javadoc/jre/technotes/guides/collections/index.html).

##### See Also

- `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html`
- `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/HashMap.html`
- `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Hashtable.html`
- `https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Comparable.html`
- `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Comparator.html`
- `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html`

### Public Constructor Summary

|---|---|
|   | [TreeMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#TreeMap())() Constructs a new, empty tree map, using the natural ordering of its keys. |
|   | [TreeMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#TreeMap(java.util.Comparator<?%20super%20K>))([Comparator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Comparator.html)\<? super K\> comparator) Constructs a new, empty tree map, ordered according to the given comparator. |
|   | [TreeMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#TreeMap(java.util.Map<?%20extends%20K,%20?%20extends%20V>))([Map](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html)\<? extends K, ? extends V\> m) Constructs a new tree map containing the same mappings as the given map, ordered according to the *natural ordering* of its keys. |
|   | [TreeMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#TreeMap(java.util.SortedMap<K,%20?%20extends%20V>))([SortedMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html)\<K, ? extends V\> m) Constructs a new tree map containing the same mappings and using the same ordering as the specified sorted map. |

### Public Method Summary

|---|---|
| [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\> | [ceilingEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#ceilingEntry(K))(K key) Returns a key-value mapping associated with the least key greater than or equal to the given key, or `null` if there is no such key. |
| K | [ceilingKey](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#ceilingKey(K))(K key) Returns the least key greater than or equal to the given key, or `null` if there is no such key. |
| void | [clear](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#clear())() Removes all of the mappings from this map. |
| [Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) | [clone](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#clone())() Returns a shallow copy of this `TreeMap` instance. |
| [Comparator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Comparator.html)\<? super K\> | [comparator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#comparator())() Returns the comparator used to order the keys in this map, or `null` if this map uses the {@linkplain Comparable natural ordering} of its keys. |
| boolean | [containsKey](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#containsKey(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) key) Returns `true` if this map contains a mapping for the specified key. |
| boolean | [containsValue](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#containsValue(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) value) Returns `true` if this map maps one or more keys to the specified value. |
| [NavigableSet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableSet.html)\<K\> | [descendingKeySet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#descendingKeySet())() Returns a reverse order `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableSet.html` view of the keys contained in this map. |
| [NavigableMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html)\<K, V\> | [descendingMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#descendingMap())() Returns a reverse order view of the mappings contained in this map. |
| [Set](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html)\<[Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\>\> | [entrySet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#entrySet())() Returns a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html` view of the mappings contained in this map. |
| [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\> | [firstEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#firstEntry())() Returns a key-value mapping associated with the least key in this map, or `null` if the map is empty. |
| K | [firstKey](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#firstKey())() Returns the first (lowest) key currently in this map. |
| [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\> | [floorEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#floorEntry(K))(K key) Returns a key-value mapping associated with the greatest key less than or equal to the given key, or `null` if there is no such key. |
| K | [floorKey](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#floorKey(K))(K key) Returns the greatest key less than or equal to the given key, or `null` if there is no such key. |
| void | [forEach](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#forEach(java.util.function.BiConsumer<?%20super%20K,%20?%20super%20V>))([BiConsumer](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/function/BiConsumer.html)\<? super K, ? super V\> action) Performs the given action for each entry in this map until all entries have been processed or the action throws an exception. |
| V | [get](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#get(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) key) Returns the value to which the specified key is mapped, or `null` if this map contains no mapping for the key. |
| [SortedMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html)\<K, V\> | [headMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#headMap(K))(K toKey) Returns a view of the portion of this map whose keys are strictly less than `toKey`. Equivalent to `headMap(toKey, false)`. |
| [NavigableMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html)\<K, V\> | [headMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#headMap(K,%20boolean))(K toKey, boolean inclusive) Returns a view of the portion of this map whose keys are less than (or equal to, if `inclusive` is true) `toKey`. |
| [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\> | [higherEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#higherEntry(K))(K key) Returns a key-value mapping associated with the least key strictly greater than the given key, or `null` if there is no such key. |
| K | [higherKey](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#higherKey(K))(K key) Returns the least key strictly greater than the given key, or `null` if there is no such key. |
| [Set](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html)\<K\> | [keySet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#keySet())() Returns a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html` view of the keys contained in this map. |
| [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\> | [lastEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#lastEntry())() Returns a key-value mapping associated with the greatest key in this map, or `null` if the map is empty. |
| K | [lastKey](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#lastKey())() Returns the last (highest) key currently in this map. |
| [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\> | [lowerEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#lowerEntry(K))(K key) Returns a key-value mapping associated with the greatest key strictly less than the given key, or `null` if there is no such key. |
| K | [lowerKey](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#lowerKey(K))(K key) Returns the greatest key strictly less than the given key, or `null` if there is no such key. |
| [NavigableSet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableSet.html)\<K\> | [navigableKeySet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#navigableKeySet())() Returns a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableSet.html` view of the keys contained in this map. |
| [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\> | [pollFirstEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#pollFirstEntry())() Removes and returns a key-value mapping associated with the least key in this map, or `null` if the map is empty. |
| [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\> | [pollLastEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#pollLastEntry())() Removes and returns a key-value mapping associated with the greatest key in this map, or `null` if the map is empty. |
| V | [put](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#put(K,%20V))(K key, V value) Associates the specified value with the specified key in this map. |
| void | [putAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#putAll(java.util.Map<?%20extends%20K,%20?%20extends%20V>))([Map](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html)\<? extends K, ? extends V\> map) Copies all of the mappings from the specified map to this map. |
| V | [remove](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#remove(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) key) Removes the mapping for this key from this TreeMap if present. |
| void | [replaceAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#replaceAll(java.util.function.BiFunction<?%20super%20K,%20?%20super%20V,%20?%20extends%20V>))([BiFunction](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/function/BiFunction.html)\<? super K, ? super V, ? extends V\> function) Replaces each entry's value with the result of invoking the given function on that entry until all entries have been processed or the function throws an exception. |
| int | [size](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#size())() Returns the number of key-value mappings in this map. |
| [SortedMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html)\<K, V\> | [subMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#subMap(K,%20K))(K fromKey, K toKey) Returns a view of the portion of this map whose keys range from `fromKey`, inclusive, to `toKey`, exclusive. Equivalent to `subMap(fromKey, true, toKey, false)`. |
| [NavigableMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html)\<K, V\> | [subMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#subMap(K,%20boolean,%20K,%20boolean))(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) Returns a view of the portion of this map whose keys range from `fromKey` to `toKey`. |
| [NavigableMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html)\<K, V\> | [tailMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#tailMap(K,%20boolean))(K fromKey, boolean inclusive) Returns a view of the portion of this map whose keys are greater than (or equal to, if `inclusive` is true) `fromKey`. |
| [SortedMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html)\<K, V\> | [tailMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#tailMap(K))(K fromKey) Returns a view of the portion of this map whose keys are greater than or equal to `fromKey`. Equivalent to `tailMap(fromKey, true)`. |
| [Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)\<V\> | [values](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#values())() Returns a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html` view of the values contained in this map. |

### Inherited Method Summary

From class [java.util.AbstractMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractMap.html)

|---|---|
| void | [clear](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractMap.html#clear())() Removes all of the mappings from this map (optional operation). |
| [Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) | [clone](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractMap.html#clone())() Returns a shallow copy of this AbstractMap instance: the keys and values themselves are not cloned. |
| boolean | [containsKey](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractMap.html#containsKey(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) key) Returns `true` if this map contains a mapping for the specified key. |
| boolean | [containsValue](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractMap.html#containsValue(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) value) Returns `true` if this map maps one or more keys to the specified value. |
| abstract [Set](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html)\<[Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\>\> | [entrySet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractMap.html#entrySet())() Returns a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html` view of the mappings contained in this map. |
| boolean | [equals](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractMap.html#equals(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) o) Compares the specified object with this map for equality. |
| V | [get](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractMap.html#get(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) key) Returns the value to which the specified key is mapped, or `null` if this map contains no mapping for the key. |
| int | [hashCode](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractMap.html#hashCode())() Returns the hash code value for this map. |
| boolean | [isEmpty](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractMap.html#isEmpty())() Returns `true` if this map contains no key-value mappings. |
| [Set](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html)\<K\> | [keySet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractMap.html#keySet())() Returns a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html` view of the keys contained in this map. |
| V | [put](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractMap.html#put(K,%20V))(K key, V value) Associates the specified value with the specified key in this map (optional operation). |
| void | [putAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractMap.html#putAll(java.util.Map<?%20extends%20K,%20?%20extends%20V>))([Map](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html)\<? extends K, ? extends V\> m) Copies all of the mappings from the specified map to this map (optional operation). |
| V | [remove](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractMap.html#remove(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) key) Removes the mapping for a key from this map if it is present (optional operation). |
| int | [size](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractMap.html#size())() Returns the number of key-value mappings in this map. |
| [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) | [toString](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractMap.html#toString())() Returns a string representation of this map. |
| [Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)\<V\> | [values](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/AbstractMap.html#values())() Returns a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html` view of the values contained in this map. |

From class [java.lang.Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html)

|---|---|
| [Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) | [clone](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#clone())() Creates and returns a copy of this `Object`. |
| boolean | [equals](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#equals(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) obj) Compares this instance with the specified object and indicates if they are equal. |
| void | [finalize](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#finalize())() Invoked when the garbage collector has detected that this instance is no longer reachable. |
| final [Class](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Class.html)\<?\> | [getClass](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#getClass())() Returns the unique instance of `https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Class.html` that represents this object's class. |
| int | [hashCode](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#hashCode())() Returns an integer hash code for this object. |
| final void | [notify](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#notify())() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up. |
| final void | [notifyAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#notifyAll())() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up. |
| [String](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/String.html) | [toString](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#toString())() Returns a string containing a concise, human-readable description of this object. |
| final void | [wait](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#wait(long,%20int))(long timeout, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires. |
| final void | [wait](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#wait(long))(long timeout) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires. |
| final void | [wait](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html#wait())() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object. |

From interface [java.util.Map](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html)

|---|---|
| abstract void | [clear](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#clear())() Removes all of the mappings from this map (optional operation). |
| V | [compute](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#compute(K,%20java.util.function.BiFunction<?%20super%20K,%20?%20super%20V,%20?%20extends%20V>))(K key, [BiFunction](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/function/BiFunction.html)\<? super K, ? super V, ? extends V\> remappingFunction) Attempts to compute a mapping for the specified key and its current mapped value (or `null` if there is no current mapping). |
| V | [computeIfAbsent](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#computeIfAbsent(K,%20java.util.function.Function<?%20super%20K,%20?%20extends%20V>))(K key, [Function](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/function/Function.html)\<? super K, ? extends V\> mappingFunction) If the specified key is not already associated with a value (or is mapped to `null`), attempts to compute its value using the given mapping function and enters it into this map unless `null`. |
| V | [computeIfPresent](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#computeIfPresent(K,%20java.util.function.BiFunction<?%20super%20K,%20?%20super%20V,%20?%20extends%20V>))(K key, [BiFunction](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/function/BiFunction.html)\<? super K, ? super V, ? extends V\> remappingFunction) If the value for the specified key is present and non-null, attempts to compute a new mapping given the key and its current mapped value. |
| abstract boolean | [containsKey](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#containsKey(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) key) Returns `true` if this map contains a mapping for the specified key. |
| abstract boolean | [containsValue](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#containsValue(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) value) Returns `true` if this map maps one or more keys to the specified value. |
| abstract [Set](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html)\<[Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\>\> | [entrySet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#entrySet())() Returns a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html` view of the mappings contained in this map. |
| abstract boolean | [equals](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#equals(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) o) Compares the specified object with this map for equality. |
| void | [forEach](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#forEach(java.util.function.BiConsumer<?%20super%20K,%20?%20super%20V>))([BiConsumer](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/function/BiConsumer.html)\<? super K, ? super V\> action) Performs the given action for each entry in this map until all entries have been processed or the action throws an exception. |
| abstract V | [get](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#get(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) key) Returns the value to which the specified key is mapped, or `null` if this map contains no mapping for the key. |
| V | [getOrDefault](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#getOrDefault(java.lang.Object,%20V))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) key, V defaultValue) Returns the value to which the specified key is mapped, or `defaultValue` if this map contains no mapping for the key. |
| abstract int | [hashCode](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#hashCode())() Returns the hash code value for this map. |
| abstract boolean | [isEmpty](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#isEmpty())() Returns `true` if this map contains no key-value mappings. |
| abstract [Set](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html)\<K\> | [keySet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#keySet())() Returns a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html` view of the keys contained in this map. |
| V | [merge](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#merge(K,%20V,%20java.util.function.BiFunction<?%20super%20V,%20?%20super%20V,%20?%20extends%20V>))(K key, V value, [BiFunction](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/function/BiFunction.html)\<? super V, ? super V, ? extends V\> remappingFunction) If the specified key is not already associated with a value or is associated with null, associates it with the given non-null value. |
| abstract V | [put](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#put(K,%20V))(K key, V value) Associates the specified value with the specified key in this map (optional operation). |
| abstract void | [putAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#putAll(java.util.Map<?%20extends%20K,%20?%20extends%20V>))([Map](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html)\<? extends K, ? extends V\> m) Copies all of the mappings from the specified map to this map (optional operation). |
| V | [putIfAbsent](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#putIfAbsent(K,%20V))(K key, V value) If the specified key is not already associated with a value (or is mapped to `null`) associates it with the given value and returns `null`, else returns the current value. |
| boolean | [remove](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#remove(java.lang.Object,%20java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) key, [Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) value) Removes the entry for the specified key only if it is currently mapped to the specified value. |
| abstract V | [remove](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#remove(java.lang.Object))([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) key) Removes the mapping for a key from this map if it is present (optional operation). |
| boolean | [replace](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#replace(K,%20V,%20V))(K key, V oldValue, V newValue) Replaces the entry for the specified key only if currently mapped to the specified value. |
| V | [replace](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#replace(K,%20V))(K key, V value) Replaces the entry for the specified key only if it is currently mapped to some value. |
| void | [replaceAll](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#replaceAll(java.util.function.BiFunction<?%20super%20K,%20?%20super%20V,%20?%20extends%20V>))([BiFunction](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/function/BiFunction.html)\<? super K, ? super V, ? extends V\> function) Replaces each entry's value with the result of invoking the given function on that entry until all entries have been processed or the function throws an exception. |
| abstract int | [size](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#size())() Returns the number of key-value mappings in this map. |
| abstract [Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)\<V\> | [values](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html#values())() Returns a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html` view of the values contained in this map. |

From interface [java.util.NavigableMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html)

|---|---|
| abstract [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\> | [ceilingEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#ceilingEntry(K))(K key) Returns a key-value mapping associated with the least key greater than or equal to the given key, or `null` if there is no such key. |
| abstract K | [ceilingKey](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#ceilingKey(K))(K key) Returns the least key greater than or equal to the given key, or `null` if there is no such key. |
| abstract [NavigableSet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableSet.html)\<K\> | [descendingKeySet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#descendingKeySet())() Returns a reverse order `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableSet.html` view of the keys contained in this map. |
| abstract [NavigableMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html)\<K, V\> | [descendingMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#descendingMap())() Returns a reverse order view of the mappings contained in this map. |
| abstract [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\> | [firstEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#firstEntry())() Returns a key-value mapping associated with the least key in this map, or `null` if the map is empty. |
| abstract [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\> | [floorEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#floorEntry(K))(K key) Returns a key-value mapping associated with the greatest key less than or equal to the given key, or `null` if there is no such key. |
| abstract K | [floorKey](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#floorKey(K))(K key) Returns the greatest key less than or equal to the given key, or `null` if there is no such key. |
| abstract [SortedMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html)\<K, V\> | [headMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#headMap(K))(K toKey) Returns a view of the portion of this map whose keys are strictly less than `toKey`. Equivalent to `headMap(toKey, false)`. |
| abstract [NavigableMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html)\<K, V\> | [headMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#headMap(K,%20boolean))(K toKey, boolean inclusive) Returns a view of the portion of this map whose keys are less than (or equal to, if `inclusive` is true) `toKey`. |
| abstract [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\> | [higherEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#higherEntry(K))(K key) Returns a key-value mapping associated with the least key strictly greater than the given key, or `null` if there is no such key. |
| abstract K | [higherKey](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#higherKey(K))(K key) Returns the least key strictly greater than the given key, or `null` if there is no such key. |
| abstract [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\> | [lastEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#lastEntry())() Returns a key-value mapping associated with the greatest key in this map, or `null` if the map is empty. |
| abstract [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\> | [lowerEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#lowerEntry(K))(K key) Returns a key-value mapping associated with the greatest key strictly less than the given key, or `null` if there is no such key. |
| abstract K | [lowerKey](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#lowerKey(K))(K key) Returns the greatest key strictly less than the given key, or `null` if there is no such key. |
| abstract [NavigableSet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableSet.html)\<K\> | [navigableKeySet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#navigableKeySet())() Returns a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableSet.html` view of the keys contained in this map. |
| abstract [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\> | [pollFirstEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#pollFirstEntry())() Removes and returns a key-value mapping associated with the least key in this map, or `null` if the map is empty. |
| abstract [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\> | [pollLastEntry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#pollLastEntry())() Removes and returns a key-value mapping associated with the greatest key in this map, or `null` if the map is empty. |
| abstract [SortedMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html)\<K, V\> | [subMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#subMap(K,%20K))(K fromKey, K toKey) Returns a view of the portion of this map whose keys range from `fromKey`, inclusive, to `toKey`, exclusive. Equivalent to `subMap(fromKey, true, toKey, false)`. |
| abstract [NavigableMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html)\<K, V\> | [subMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#subMap(K,%20boolean,%20K,%20boolean))(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) Returns a view of the portion of this map whose keys range from `fromKey` to `toKey`. |
| abstract [NavigableMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html)\<K, V\> | [tailMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#tailMap(K,%20boolean))(K fromKey, boolean inclusive) Returns a view of the portion of this map whose keys are greater than (or equal to, if `inclusive` is true) `fromKey`. |
| abstract [SortedMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html)\<K, V\> | [tailMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html#tailMap(K))(K fromKey) Returns a view of the portion of this map whose keys are greater than or equal to `fromKey`. Equivalent to `tailMap(fromKey, true)`. |

From interface [java.util.SortedMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html)

|---|---|
| abstract [Comparator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Comparator.html)\<? super K\> | [comparator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html#comparator())() Returns the comparator used to order the keys in this map, or `null` if this map uses the {@linkplain Comparable natural ordering} of its keys. |
| abstract [Set](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html)\<[Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\>\> | [entrySet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html#entrySet())() Returns a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html` view of the mappings contained in this map. |
| abstract K | [firstKey](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html#firstKey())() Returns the first (lowest) key currently in this map. |
| abstract [SortedMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html)\<K, V\> | [headMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html#headMap(K))(K toKey) Returns a view of the portion of this map whose keys are strictly less than `toKey`. |
| abstract [Set](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html)\<K\> | [keySet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html#keySet())() Returns a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html` view of the keys contained in this map. |
| abstract K | [lastKey](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html#lastKey())() Returns the last (highest) key currently in this map. |
| abstract [SortedMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html)\<K, V\> | [subMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html#subMap(K,%20K))(K fromKey, K toKey) Returns a view of the portion of this map whose keys range from `fromKey`, inclusive, to `toKey`, exclusive. |
| abstract [SortedMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html)\<K, V\> | [tailMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html#tailMap(K))(K fromKey) Returns a view of the portion of this map whose keys are greater than or equal to `fromKey`. |
| abstract [Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)\<V\> | [values](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html#values())() Returns a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html` view of the values contained in this map. |

## Public Constructors

#### public
**TreeMap**
()

Constructs a new, empty tree map, using the natural ordering of its
keys. All keys inserted into the map must implement the `https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Comparable.html` interface. Furthermore, all such keys must be
*mutually comparable* : `k1.compareTo(k2)` must not throw
a `ClassCastException` for any keys `k1` and
`k2` in the map. If the user attempts to put a key into the
map that violates this constraint (for example, the user attempts to
put a string key into a map whose keys are integers), the
`put(Object key, Object value)` call will throw a
`ClassCastException`.

#### public
**TreeMap**
([Comparator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Comparator.html)\<? super K\> comparator)

Constructs a new, empty tree map, ordered according to the given
comparator. All keys inserted into the map must be *mutually
comparable* by the given comparator: `comparator.compare(k1,
k2)` must not throw a `ClassCastException` for any keys
`k1` and `k2` in the map. If the user attempts to put
a key into the map that violates this constraint, the `put(Object
key, Object value)` call will throw a
`ClassCastException`.

##### Parameters

| comparator | the comparator that will be used to order this map. If `null`, the {@linkplain Comparable natural ordering} of the keys will be used. |
|---|---|

#### public
**TreeMap**
([Map](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html)\<? extends K, ? extends V\> m)

Constructs a new tree map containing the same mappings as the given
map, ordered according to the *natural ordering* of its keys.
All keys inserted into the new map must implement the `https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Comparable.html` interface. Furthermore, all such keys must be
*mutually comparable* : `k1.compareTo(k2)` must not throw
a `ClassCastException` for any keys `k1` and
`k2` in the map. This method runs in n\*log(n) time.

##### Parameters

| m | the map whose mappings are to be placed in this map |
|---|---|

##### Throws

| [ClassCastException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ClassCastException.html) | if the keys in m are not `https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Comparable.html`, or are not mutually comparable |
| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if the specified map is null |
|---|---|

#### public
**TreeMap**
([SortedMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html)\<K, ? extends V\> m)

Constructs a new tree map containing the same mappings and
using the same ordering as the specified sorted map. This
method runs in linear time.

##### Parameters

| m | the sorted map whose mappings are to be placed in this map, and whose comparator is to be used to sort this map |
|---|---|

##### Throws

| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if the specified map is null |
|---|---|

## Public Methods

#### public [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\>
**ceilingEntry**
(K key)

Returns a key-value mapping associated with the least key
greater than or equal to the given key, or `null` if
there is no such key.

##### Parameters

| key | the key |
|---|---|

##### Returns

- an entry with the least key greater than or equal to `key`, or `null` if there is no such key

##### Throws

| [ClassCastException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ClassCastException.html) |   |
| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys |
|---|---|

#### public K
**ceilingKey**
(K key)

Returns the least key greater than or equal to the given key,
or `null` if there is no such key.

##### Parameters

| key | the key |
|---|---|

##### Returns

- the least key greater than or equal to `key`, or `null` if there is no such key

##### Throws

| [ClassCastException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ClassCastException.html) |   |
| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys |
|---|---|

#### public void
**clear**
()

Removes all of the mappings from this map.
The map will be empty after this call returns.

#### public [Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html)
**clone**
()

Returns a shallow copy of this `TreeMap` instance. (The keys and
values themselves are not cloned.)

##### Returns

- a shallow copy of this map

#### public [Comparator](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Comparator.html)\<? super K\>
**comparator**
()

Returns the comparator used to order the keys in this map, or
`null` if this map uses the {@linkplain Comparable
natural ordering} of its keys.

##### Returns

- the comparator used to order the keys in this map, or `null` if this map uses the natural ordering of its keys

#### public boolean
**containsKey**
([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) key)

Returns `true` if this map contains a mapping for the specified
key.

##### Parameters

| key | key whose presence in this map is to be tested |
|---|---|

##### Returns

- `true` if this map contains a mapping for the specified key

##### Throws

| [ClassCastException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ClassCastException.html) | if the specified key cannot be compared with the keys currently in the map |
| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys |
|---|---|

#### public boolean
**containsValue**
([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) value)

Returns `true` if this map maps one or more keys to the
specified value. More formally, returns `true` if and only if
this map contains at least one mapping to a value `v` such
that `(value==null ? v==null : value.equals(v))`. This
operation will probably require time linear in the map size for
most implementations.

##### Parameters

| value | value whose presence in this map is to be tested |
|---|---|

##### Returns

- `true` if a mapping to `value` exists; `false` otherwise

#### public [NavigableSet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableSet.html)\<K\>
**descendingKeySet**
()

Returns a reverse order `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableSet.html` view of the keys contained in this map.
The set's iterator returns the keys in descending order.
The set is backed by the map, so changes to the map are reflected in
the set, and vice-versa. If the map is modified while an iteration
over the set is in progress (except through the iterator's own `remove` operation), the results of the iteration are undefined. The
set supports element removal, which removes the corresponding mapping
from the map, via the `Iterator.remove`, `Set.remove`,
`removeAll`, `retainAll`, and `clear` operations.
It does not support the `add` or `addAll` operations.

##### Returns

- a reverse order navigable set view of the keys in this map

#### public [NavigableMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html)\<K, V\>
**descendingMap**
()

Returns a reverse order view of the mappings contained in this map.
The descending map is backed by this map, so changes to the map are
reflected in the descending map, and vice-versa. If either map is
modified while an iteration over a collection view of either map
is in progress (except through the iterator's own `remove`
operation), the results of the iteration are undefined.

The returned map has an ordering equivalent to
`https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collections.html#reverseOrder(java.util.Comparator<T>)``(comparator())`.
The expression `m.descendingMap().descendingMap()` returns a
view of `m` essentially equivalent to `m`.

##### Returns

- a reverse order view of this map

#### public [Set](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html)\<[Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\>\>
**entrySet**
()

Returns a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html` view of the mappings contained in this map.

The set's iterator returns the entries in ascending key order. The
sets's spliterator is
*[late-binding](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator#binding)* ,
*fail-fast* , and additionally reports `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator.html#SORTED` and
`https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator.html#ORDERED` with an encounter order that is ascending key
order.

The set is backed by the map, so changes to the map are
reflected in the set, and vice-versa. If the map is modified
while an iteration over the set is in progress (except through
the iterator's own `remove` operation, or through the
`setValue` operation on a map entry returned by the
iterator) the results of the iteration are undefined. The set
supports element removal, which removes the corresponding
mapping from the map, via the `Iterator.remove`,
`Set.remove`, `removeAll`, `retainAll` and
`clear` operations. It does not support the
`add` or `addAll` operations.

##### Returns

- a set view of the mappings contained in this map

#### public [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\>
**firstEntry**
()

Returns a key-value mapping associated with the least
key in this map, or `null` if the map is empty.

##### Returns

- an entry with the least key, or `null` if this map is empty

#### public K
**firstKey**
()

Returns the first (lowest) key currently in this map.

##### Returns

- the first (lowest) key currently in this map

##### Throws

| [NoSuchElementException](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NoSuchElementException.html) |   |
|---|---|

#### public [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\>
**floorEntry**
(K key)

Returns a key-value mapping associated with the greatest key
less than or equal to the given key, or `null` if there
is no such key.

##### Parameters

| key | the key |
|---|---|

##### Returns

- an entry with the greatest key less than or equal to `key`, or `null` if there is no such key

##### Throws

| [ClassCastException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ClassCastException.html) |   |
| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys |
|---|---|

#### public K
**floorKey**
(K key)

Returns the greatest key less than or equal to the given key,
or `null` if there is no such key.

##### Parameters

| key | the key |
|---|---|

##### Returns

- the greatest key less than or equal to `key`, or `null` if there is no such key

##### Throws

| [ClassCastException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ClassCastException.html) |   |
| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys |
|---|---|

#### public void
**forEach**
([BiConsumer](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/function/BiConsumer.html)\<? super K, ? super V\> action)

Performs the given action for each entry in this map until all entries
have been processed or the action throws an exception. Unless
otherwise specified by the implementing class, actions are performed in
the order of entry set iteration (if an iteration order is specified.)
Exceptions thrown by the action are relayed to the caller.

##### Parameters

| action | The action to be performed for each entry |
|---|---|

#### public V
**get**
([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) key)

Returns the value to which the specified key is mapped,
or `null` if this map contains no mapping for the key.

More formally, if this map contains a mapping from a key
`k` to a value `v` such that `key` compares
equal to `k` according to the map's ordering, then this
method returns `v`; otherwise it returns `null`.
(There can be at most one such mapping.)

A return value of `null` does not *necessarily*
indicate that the map contains no mapping for the key; it's also
possible that the map explicitly maps the key to `null`.
The `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#containsKey(java.lang.Object)` operation may be used to
distinguish these two cases.

##### Parameters

| key | the key whose associated value is to be returned |
|---|---|

##### Returns

- the value to which the specified key is mapped, or `null` if this map contains no mapping for the key

##### Throws

| [ClassCastException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ClassCastException.html) | if the specified key cannot be compared with the keys currently in the map |
| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys |
|---|---|

#### public [SortedMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html)\<K, V\>
**headMap**
(K toKey)

Returns a view of the portion of this map whose keys are
strictly less than `toKey`. The returned map is backed
by this map, so changes in the returned map are reflected in
this map, and vice-versa. The returned map supports all
optional map operations that this map supports.

The returned map will throw an `IllegalArgumentException`
on an attempt to insert a key outside its range.

Equivalent to `headMap(toKey, false)`.

##### Parameters

| toKey | high endpoint (exclusive) of the keys in the returned map |
|---|---|

##### Returns

- a view of the portion of this map whose keys are strictly less than `toKey`

##### Throws

| [ClassCastException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ClassCastException.html) |   |
| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if `toKey` is null and this map uses natural ordering, or its comparator does not permit null keys |
| [IllegalArgumentException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/IllegalArgumentException.html) |   |
|---|---|

#### public [NavigableMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html)\<K, V\>
**headMap**
(K toKey, boolean inclusive)

Returns a view of the portion of this map whose keys are less than (or
equal to, if `inclusive` is true) `toKey`. The returned
map is backed by this map, so changes in the returned map are reflected
in this map, and vice-versa. The returned map supports all optional
map operations that this map supports.

The returned map will throw an `IllegalArgumentException`
on an attempt to insert a key outside its range.

##### Parameters

| toKey | high endpoint of the keys in the returned map |
| inclusive | `true` if the high endpoint is to be included in the returned view |
|---|---|

##### Returns

- a view of the portion of this map whose keys are less than (or equal to, if `inclusive` is true) `toKey`

##### Throws

| [ClassCastException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ClassCastException.html) |   |
| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if `toKey` is null and this map uses natural ordering, or its comparator does not permit null keys |
| [IllegalArgumentException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/IllegalArgumentException.html) |   |
|---|---|

#### public [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\>
**higherEntry**
(K key)

Returns a key-value mapping associated with the least key
strictly greater than the given key, or `null` if there
is no such key.

##### Parameters

| key | the key |
|---|---|

##### Returns

- an entry with the least key greater than `key`, or `null` if there is no such key

##### Throws

| [ClassCastException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ClassCastException.html) |   |
| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys |
|---|---|

#### public K
**higherKey**
(K key)

Returns the least key strictly greater than the given key, or
`null` if there is no such key.

##### Parameters

| key | the key |
|---|---|

##### Returns

- the least key greater than `key`, or `null` if there is no such key

##### Throws

| [ClassCastException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ClassCastException.html) |   |
| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys |
|---|---|

#### public [Set](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html)\<K\>
**keySet**
()

Returns a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Set.html` view of the keys contained in this map.

The set's iterator returns the keys in ascending order.
The set's spliterator is
*[late-binding](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator#binding)* ,
*fail-fast* , and additionally reports `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator.html#SORTED`
and `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator.html#ORDERED` with an encounter order that is ascending
key order. The spliterator's comparator (see
`https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator.html#getComparator()`) is `null` if
the tree map's comparator (see `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/TreeMap.html#comparator()`) is `null`.
Otherwise, the spliterator's comparator is the same as or imposes the
same total ordering as the tree map's comparator.

The set is backed by the map, so changes to the map are
reflected in the set, and vice-versa. If the map is modified
while an iteration over the set is in progress (except through
the iterator's own `remove` operation), the results of
the iteration are undefined. The set supports element removal,
which removes the corresponding mapping from the map, via the
`Iterator.remove`, `Set.remove`,
`removeAll`, `retainAll`, and `clear`
operations. It does not support the `add` or `addAll`
operations.

##### Returns

- a set view of the keys contained in this map

#### public [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\>
**lastEntry**
()

Returns a key-value mapping associated with the greatest
key in this map, or `null` if the map is empty.

##### Returns

- an entry with the greatest key, or `null` if this map is empty

#### public K
**lastKey**
()

Returns the last (highest) key currently in this map.

##### Returns

- the last (highest) key currently in this map

##### Throws

| [NoSuchElementException](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NoSuchElementException.html) |   |
|---|---|

#### public [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\>
**lowerEntry**
(K key)

Returns a key-value mapping associated with the greatest key
strictly less than the given key, or `null` if there is
no such key.

##### Parameters

| key | the key |
|---|---|

##### Returns

- an entry with the greatest key less than `key`, or `null` if there is no such key

##### Throws

| [ClassCastException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ClassCastException.html) |   |
| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys |
|---|---|

#### public K
**lowerKey**
(K key)

Returns the greatest key strictly less than the given key, or
`null` if there is no such key.

##### Parameters

| key | the key |
|---|---|

##### Returns

- the greatest key less than `key`, or `null` if there is no such key

##### Throws

| [ClassCastException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ClassCastException.html) |   |
| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys |
|---|---|

#### public [NavigableSet](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableSet.html)\<K\>
**navigableKeySet**
()

Returns a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableSet.html` view of the keys contained in this map.
The set's iterator returns the keys in ascending order.
The set is backed by the map, so changes to the map are reflected in
the set, and vice-versa. If the map is modified while an iteration
over the set is in progress (except through the iterator's own `remove` operation), the results of the iteration are undefined. The
set supports element removal, which removes the corresponding mapping
from the map, via the `Iterator.remove`, `Set.remove`,
`removeAll`, `retainAll`, and `clear` operations.
It does not support the `add` or `addAll` operations.

##### Returns

- a navigable set view of the keys in this map

#### public [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\>
**pollFirstEntry**
()

Removes and returns a key-value mapping associated with
the least key in this map, or `null` if the map is empty.

##### Returns

- the removed first entry of this map, or `null` if this map is empty

#### public [Entry](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.Entry.html)\<K, V\>
**pollLastEntry**
()

Removes and returns a key-value mapping associated with
the greatest key in this map, or `null` if the map is empty.

##### Returns

- the removed last entry of this map, or `null` if this map is empty

#### public V
**put**
(K key, V value)

Associates the specified value with the specified key in this map.
If the map previously contained a mapping for the key, the old
value is replaced.

##### Parameters

| key | key with which the specified value is to be associated |
| value | value to be associated with the specified key |
|---|---|

##### Returns

- the previous value associated with `key`, or `null` if there was no mapping for `key`. (A `null` return can also indicate that the map previously associated `null` with `key`.)

##### Throws

| [ClassCastException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ClassCastException.html) | if the specified key cannot be compared with the keys currently in the map |
| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys |
|---|---|

#### public void
**putAll**
([Map](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Map.html)\<? extends K, ? extends V\> map)

Copies all of the mappings from the specified map to this map.
These mappings replace any mappings that this map had for any
of the keys currently in the specified map.

##### Parameters

| map | mappings to be stored in this map |
|---|---|

##### Throws

| [ClassCastException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ClassCastException.html) | if the class of a key or value in the specified map prevents it from being stored in this map |
| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if the specified map is null or the specified map contains a null key and this map does not permit null keys |
|---|---|

#### public V
**remove**
([Object](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/Object.html) key)

Removes the mapping for this key from this TreeMap if present.

##### Parameters

| key | key for which mapping should be removed |
|---|---|

##### Returns

- the previous value associated with `key`, or `null` if there was no mapping for `key`. (A `null` return can also indicate that the map previously associated `null` with `key`.)

##### Throws

| [ClassCastException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ClassCastException.html) | if the specified key cannot be compared with the keys currently in the map |
| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys |
|---|---|

#### public void
**replaceAll**
([BiFunction](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/function/BiFunction.html)\<? super K, ? super V, ? extends V\> function)

Replaces each entry's value with the result of invoking the given
function on that entry until all entries have been processed or the
function throws an exception. Exceptions thrown by the function are
relayed to the caller.

##### Parameters

| function | the function to apply to each entry |
|---|---|

#### public int
**size**
()

Returns the number of key-value mappings in this map.

##### Returns

- the number of key-value mappings in this map

#### public [SortedMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html)\<K, V\>
**subMap**
(K fromKey, K toKey)

Returns a view of the portion of this map whose keys range from
`fromKey`, inclusive, to `toKey`, exclusive. (If
`fromKey` and `toKey` are equal, the returned map
is empty.) The returned map is backed by this map, so changes
in the returned map are reflected in this map, and vice-versa.
The returned map supports all optional map operations that this
map supports.

The returned map will throw an `IllegalArgumentException`
on an attempt to insert a key outside its range.

Equivalent to `subMap(fromKey, true, toKey, false)`.

##### Parameters

| fromKey | low endpoint (inclusive) of the keys in the returned map |
| toKey | high endpoint (exclusive) of the keys in the returned map |
|---|---|

##### Returns

- a view of the portion of this map whose keys range from `fromKey`, inclusive, to `toKey`, exclusive

##### Throws

| [ClassCastException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ClassCastException.html) |   |
| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if `fromKey` or `toKey` is null and this map uses natural ordering, or its comparator does not permit null keys |
| [IllegalArgumentException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/IllegalArgumentException.html) |   |
|---|---|

#### public [NavigableMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html)\<K, V\>
**subMap**
(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive)

Returns a view of the portion of this map whose keys range from
`fromKey` to `toKey`. If `fromKey` and
`toKey` are equal, the returned map is empty unless
`fromInclusive` and `toInclusive` are both true. The
returned map is backed by this map, so changes in the returned map are
reflected in this map, and vice-versa. The returned map supports all
optional map operations that this map supports.

The returned map will throw an `IllegalArgumentException`
on an attempt to insert a key outside of its range, or to construct a
submap either of whose endpoints lie outside its range.

##### Parameters

| fromKey | low endpoint of the keys in the returned map |
| fromInclusive | `true` if the low endpoint is to be included in the returned view |
| toKey | high endpoint of the keys in the returned map |
| toInclusive | `true` if the high endpoint is to be included in the returned view |
|---|---|

##### Returns

- a view of the portion of this map whose keys range from `fromKey` to `toKey`

##### Throws

| [ClassCastException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ClassCastException.html) |   |
| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if `fromKey` or `toKey` is null and this map uses natural ordering, or its comparator does not permit null keys |
| [IllegalArgumentException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/IllegalArgumentException.html) |   |
|---|---|

#### public [NavigableMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/NavigableMap.html)\<K, V\>
**tailMap**
(K fromKey, boolean inclusive)

Returns a view of the portion of this map whose keys are greater than (or
equal to, if `inclusive` is true) `fromKey`. The returned
map is backed by this map, so changes in the returned map are reflected
in this map, and vice-versa. The returned map supports all optional
map operations that this map supports.

The returned map will throw an `IllegalArgumentException`
on an attempt to insert a key outside its range.

##### Parameters

| fromKey | low endpoint of the keys in the returned map |
| inclusive | `true` if the low endpoint is to be included in the returned view |
|---|---|

##### Returns

- a view of the portion of this map whose keys are greater than (or equal to, if `inclusive` is true) `fromKey`

##### Throws

| [ClassCastException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ClassCastException.html) |   |
| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if `fromKey` is null and this map uses natural ordering, or its comparator does not permit null keys |
| [IllegalArgumentException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/IllegalArgumentException.html) |   |
|---|---|

#### public [SortedMap](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/SortedMap.html)\<K, V\>
**tailMap**
(K fromKey)

Returns a view of the portion of this map whose keys are
greater than or equal to `fromKey`. The returned map is
backed by this map, so changes in the returned map are
reflected in this map, and vice-versa. The returned map
supports all optional map operations that this map supports.

The returned map will throw an `IllegalArgumentException`
on an attempt to insert a key outside its range.

Equivalent to `tailMap(fromKey, true)`.

##### Parameters

| fromKey | low endpoint (inclusive) of the keys in the returned map |
|---|---|

##### Returns

- a view of the portion of this map whose keys are greater than or equal to `fromKey`

##### Throws

| [ClassCastException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/ClassCastException.html) |   |
| [NullPointerException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/NullPointerException.html) | if `fromKey` is null and this map uses natural ordering, or its comparator does not permit null keys |
| [IllegalArgumentException](https://developers.google.com/j2objc/javadoc/jre/reference/java/lang/IllegalArgumentException.html) |   |
|---|---|

#### public [Collection](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html)\<V\>
**values**
()

Returns a `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Collection.html` view of the values contained in this map.

The collection's iterator returns the values in ascending order
of the corresponding keys. The collection's spliterator is
*[late-binding](https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator#binding)* ,
*fail-fast* , and additionally reports `https://developers.google.com/j2objc/javadoc/jre/reference/java/util/Spliterator.html#ORDERED`
with an encounter order that is ascending order of the corresponding
keys.

The collection is backed by the map, so changes to the map are
reflected in the collection, and vice-versa. If the map is
modified while an iteration over the collection is in progress
(except through the iterator's own `remove` operation),
the results of the iteration are undefined. The collection
supports element removal, which removes the corresponding
mapping from the map, via the `Iterator.remove`,
`Collection.remove`, `removeAll`,
`retainAll` and `clear` operations. It does not
support the `add` or `addAll` operations.

##### Returns

- a collection view of the values contained in this map