JSONArray

public class JSONArray extends Object

A dense indexed sequence of values. Values may be any mix of JSONObjects, other JSONArrays, Strings, Booleans, Integers, Longs, Doubles, null or NULL. Values may not be NaNs, infinities, or of any type not listed here.

JSONArray has the same type coercion behavior and optional/mandatory accessors as JSONObject. See that class' documentation for details.

Warning: this class represents null in two incompatible ways: the standard Java null reference, and the sentinel value NULL. In particular, get fails if the requested index holds the null reference, but succeeds if it holds JSONObject.NULL.

Instances of this class are not thread safe. Although this class is nonfinal, it was not designed for inheritance and should not be subclassed. In particular, self-use by overridable methods is not specified. See Effective Java Item 17, "Design and Document or inheritance or else prohibit it" for further information.

Public Constructor Summary

JSONArray()
Creates a JSONArray with no values.
JSONArray(Collection copyFrom)
Creates a new JSONArray by copying all values from the given collection.
JSONArray(JSONTokener readFrom)
Creates a new JSONArray with values from the next array in the tokener.
JSONArray(String json)
Creates a new JSONArray with values from the JSON string.
JSONArray(Object array)
Creates a new JSONArray with values from the given primitive array.

Public Method Summary

boolean
equals(Object o)
Object
get(int index)
Returns the value at index.
boolean
getBoolean(int index)
Returns the value at index if it exists and is a boolean or can be coerced to a boolean.
double
getDouble(int index)
Returns the value at index if it exists and is a double or can be coerced to a double.
int
getInt(int index)
Returns the value at index if it exists and is an int or can be coerced to an int.
JSONArray
getJSONArray(int index)
Returns the value at index if it exists and is a JSONArray.
JSONObject
getJSONObject(int index)
Returns the value at index if it exists and is a JSONObject.
long
getLong(int index)
Returns the value at index if it exists and is a long or can be coerced to a long.
String
getString(int index)
Returns the value at index if it exists, coercing it if necessary.
int
boolean
isNull(int index)
Returns true if this array has no value at index, or if its value is the null reference or NULL.
String
join(String separator)
Returns a new string by alternating this array's values with separator.
int
length()
Returns the number of values in this array.
Object
opt(int index)
Returns the value at index, or null if the array has no value at index.
boolean
optBoolean(int index)
Returns the value at index if it exists and is a boolean or can be coerced to a boolean.
boolean
optBoolean(int index, boolean fallback)
Returns the value at index if it exists and is a boolean or can be coerced to a boolean.
double
optDouble(int index)
Returns the value at index if it exists and is a double or can be coerced to a double.
double
optDouble(int index, double fallback)
Returns the value at index if it exists and is a double or can be coerced to a double.
int
optInt(int index)
Returns the value at index if it exists and is an int or can be coerced to an int.
int
optInt(int index, int fallback)
Returns the value at index if it exists and is an int or can be coerced to an int.
JSONArray
optJSONArray(int index)
Returns the value at index if it exists and is a JSONArray.
JSONObject
optJSONObject(int index)
Returns the value at index if it exists and is a JSONObject.
long
optLong(int index)
Returns the value at index if it exists and is a long or can be coerced to a long.
long
optLong(int index, long fallback)
Returns the value at index if it exists and is a long or can be coerced to a long.
String
optString(int index)
Returns the value at index if it exists, coercing it if necessary.
String
optString(int index, String fallback)
Returns the value at index if it exists, coercing it if necessary.
JSONArray
put(int value)
Appends value to the end of this array.
JSONArray
put(long value)
Appends value to the end of this array.
JSONArray
put(int index, boolean value)
Sets the value at index to value, null padding this array to the required length if necessary.
JSONArray
put(double value)
Appends value to the end of this array.
JSONArray
put(int index, Object value)
Sets the value at index to value, null padding this array to the required length if necessary.
JSONArray
put(int index, long value)
Sets the value at index to value, null padding this array to the required length if necessary.
JSONArray
put(int index, int value)
Sets the value at index to value, null padding this array to the required length if necessary.
JSONArray
put(boolean value)
Appends value to the end of this array.
JSONArray
put(int index, double value)
Sets the value at index to value, null padding this array to the required length if necessary.
JSONArray
put(Object value)
Appends value to the end of this array.
Object
remove(int index)
Removes and returns the value at index, or null if the array has no value at index.
JSONObject
toJSONObject(JSONArray names)
Returns a new object whose values are the values in this array, and whose names are the values in names.
String
toString()
Encodes this array as a compact JSON string, such as:
[94043,90210]
String
toString(int indentSpaces)
Encodes this array as a human readable JSON string for debugging, such as:
 [
     94043,
     90210
 ]

Inherited Method Summary

Public Constructors

public JSONArray ()

Creates a JSONArray with no values.

public JSONArray (Collection copyFrom)

Creates a new JSONArray by copying all values from the given collection.

Parameters
copyFrom a collection whose values are of supported types. Unsupported values are not permitted and will yield an array in an inconsistent state.

public JSONArray (JSONTokener readFrom)

Creates a new JSONArray with values from the next array in the tokener.

Parameters
readFrom a tokener whose nextValue() method will yield a JSONArray.
Throws
JSONException if the parse fails or doesn't yield a JSONArray.

public JSONArray (String json)

Creates a new JSONArray with values from the JSON string.

Parameters
json a JSON-encoded string containing an array.
Throws
JSONException if the parse fails or doesn't yield a JSONArray.

public JSONArray (Object array)

Creates a new JSONArray with values from the given primitive array.

Parameters
array
Throws
JSONException

Public Methods

public boolean equals (Object o)

Parameters
o

public Object get (int index)

Returns the value at index.

Parameters
index
Throws
JSONException if this array has no value at index, or if that value is the null reference. This method returns normally if the value is JSONObject#NULL.

public boolean getBoolean (int index)

Returns the value at index if it exists and is a boolean or can be coerced to a boolean.

Parameters
index
Throws
JSONException if the value at index doesn't exist or cannot be coerced to a boolean.

public double getDouble (int index)

Returns the value at index if it exists and is a double or can be coerced to a double.

Parameters
index
Throws
JSONException if the value at index doesn't exist or cannot be coerced to a double.

public int getInt (int index)

Returns the value at index if it exists and is an int or can be coerced to an int.

Parameters
index
Throws
JSONException if the value at index doesn't exist or cannot be coerced to a int.

public JSONArray getJSONArray (int index)

Returns the value at index if it exists and is a JSONArray.

Parameters
index
Throws
JSONException if the value doesn't exist or is not a JSONArray.

public JSONObject getJSONObject (int index)

Returns the value at index if it exists and is a JSONObject.

Parameters
index
Throws
JSONException if the value doesn't exist or is not a JSONObject.

public long getLong (int index)

Returns the value at index if it exists and is a long or can be coerced to a long.

Parameters
index
Throws
JSONException if the value at index doesn't exist or cannot be coerced to a long.

public String getString (int index)

Returns the value at index if it exists, coercing it if necessary.

Parameters
index
Throws
JSONException if no such value exists.

public int hashCode ()

public boolean isNull (int index)

Returns true if this array has no value at index, or if its value is the null reference or NULL.

Parameters
index

public String join (String separator)

Returns a new string by alternating this array's values with separator. This array's string values are quoted and have their special characters escaped. For example, the array containing the strings '12" pizza', 'taco' and 'soda' joined on '+' returns this:

"12\" pizza"+"taco"+"soda"

Parameters
separator
Throws
JSONException

public int length ()

Returns the number of values in this array.

public Object opt (int index)

Returns the value at index, or null if the array has no value at index.

Parameters
index

public boolean optBoolean (int index)

Returns the value at index if it exists and is a boolean or can be coerced to a boolean. Returns false otherwise.

Parameters
index

public boolean optBoolean (int index, boolean fallback)

Returns the value at index if it exists and is a boolean or can be coerced to a boolean. Returns fallback otherwise.

Parameters
index
fallback

public double optDouble (int index)

Returns the value at index if it exists and is a double or can be coerced to a double. Returns NaN otherwise.

Parameters
index

public double optDouble (int index, double fallback)

Returns the value at index if it exists and is a double or can be coerced to a double. Returns fallback otherwise.

Parameters
index
fallback

public int optInt (int index)

Returns the value at index if it exists and is an int or can be coerced to an int. Returns 0 otherwise.

Parameters
index

public int optInt (int index, int fallback)

Returns the value at index if it exists and is an int or can be coerced to an int. Returns fallback otherwise.

Parameters
index
fallback

public JSONArray optJSONArray (int index)

Returns the value at index if it exists and is a JSONArray. Returns null otherwise.

Parameters
index

public JSONObject optJSONObject (int index)

Returns the value at index if it exists and is a JSONObject. Returns null otherwise.

Parameters
index

public long optLong (int index)

Returns the value at index if it exists and is a long or can be coerced to a long. Returns 0 otherwise.

Parameters
index

public long optLong (int index, long fallback)

Returns the value at index if it exists and is a long or can be coerced to a long. Returns fallback otherwise.

Parameters
index
fallback

public String optString (int index)

Returns the value at index if it exists, coercing it if necessary. Returns the empty string if no such value exists.

Parameters
index

public String optString (int index, String fallback)

Returns the value at index if it exists, coercing it if necessary. Returns fallback if no such value exists.

Parameters
index
fallback

public JSONArray put (int value)

Appends value to the end of this array.

Parameters
value
Returns
  • this array.

public JSONArray put (long value)

Appends value to the end of this array.

Parameters
value
Returns
  • this array.

public JSONArray put (int index, boolean value)

Sets the value at index to value, null padding this array to the required length if necessary. If a value already exists at index, it will be replaced.

Parameters
index
value
Returns
  • this array.
Throws
JSONException

public JSONArray put (double value)

Appends value to the end of this array.

Parameters
value a finite value. May not be NaNs or infinities.
Returns
  • this array.
Throws
JSONException

public JSONArray put (int index, Object value)

Sets the value at index to value, null padding this array to the required length if necessary. If a value already exists at index, it will be replaced.

Parameters
index
value a JSONObject, JSONArray, String, Boolean, Integer, Long, Double, NULL, or null. May not be NaNs or infinities.
Returns
  • this array.
Throws
JSONException

public JSONArray put (int index, long value)

Sets the value at index to value, null padding this array to the required length if necessary. If a value already exists at index, it will be replaced.

Parameters
index
value
Returns
  • this array.
Throws
JSONException

public JSONArray put (int index, int value)

Sets the value at index to value, null padding this array to the required length if necessary. If a value already exists at index, it will be replaced.

Parameters
index
value
Returns
  • this array.
Throws
JSONException

public JSONArray put (boolean value)

Appends value to the end of this array.

Parameters
value
Returns
  • this array.

public JSONArray put (int index, double value)

Sets the value at index to value, null padding this array to the required length if necessary. If a value already exists at index, it will be replaced.

Parameters
index
value a finite value. May not be NaNs or infinities.
Returns
  • this array.
Throws
JSONException

public JSONArray put (Object value)

Appends value to the end of this array.

Parameters
value a JSONObject, JSONArray, String, Boolean, Integer, Long, Double, NULL, or null. May not be NaNs or infinities. Unsupported values are not permitted and will cause the array to be in an inconsistent state.
Returns
  • this array.

public Object remove (int index)

Removes and returns the value at index, or null if the array has no value at index.

Parameters
index

public JSONObject toJSONObject (JSONArray names)

Returns a new object whose values are the values in this array, and whose names are the values in names. Names and values are paired up by index from 0 through to the shorter array's length. Names that are not strings will be coerced to strings. This method returns null if either array is empty.

Parameters
names
Throws
JSONException

public String toString ()

Encodes this array as a compact JSON string, such as:

[94043,90210]

public String toString (int indentSpaces)

Encodes this array as a human readable JSON string for debugging, such as:

 [
     94043,
     90210
 ]

Parameters
indentSpaces the number of spaces to indent for each level of nesting.
Throws
JSONException