public class SparseLongArray extends Object
implements Cloneable

SparseLongArrays map integers to longs. Unlike a normal array of longs, there can be gaps in the indices. It is intended to be more memory efficient than using a HashMap to map Integers to Longs, both because it avoids auto-boxing keys and values and its data structure doesn't rely on an extra entry object for each mapping.

Note that this container keeps its mappings in an array data structure, using a binary search to find keys. The implementation is not intended to be appropriate for data structures that may contain large numbers of items. It is generally slower than a traditional HashMap, since lookups require a binary search and adds and removes require inserting and deleting entries in the array. For containers holding up to hundreds of items, the performance difference is not significant, less than 50%.

It is possible to iterate over the items in this container using keyAt(int) and valueAt(int). Iterating over the keys using keyAt(int) with ascending values of the index will return the keys in ascending order, or the values corresponding to the keys in ascending order in the case of valueAt(int).

Public Constructor Summary

Creates a new SparseLongArray containing no mappings.
SparseLongArray(int initialCapacity)
Creates a new SparseLongArray containing no mappings that will not require any additional memory allocation to store the specified number of mappings.

Public Method Summary

append(int key, long value)
Puts a key/value pair into the array, optimizing for the case where the key is greater than all existing keys in the array.
Removes all key-value mappings from this SparseIntArray.
delete(int key)
Removes the mapping from the specified key, if there was any.
get(int key)
Gets the long mapped from the specified key, or 0 if no such mapping has been made.
get(int key, long valueIfKeyNotFound)
Gets the long mapped from the specified key, or the specified value if no such mapping has been made.