Array | API reference | Android Developers

public final class Array
extends Object

The Array class provides static methods to dynamically create and access Java arrays.

Array permits widening conversions to occur during a get or set operation, but throws an IllegalArgumentException if a narrowing conversion would occur.

Summary

Public methods
`static Object`	`get(Object array, int index)` Returns the value of the indexed component in the specified array object.
`static boolean`	`getBoolean(Object array, int index)` Returns the value of the indexed component in the specified array object, as a `boolean`.
`static byte`	`getByte(Object array, int index)` Returns the value of the indexed component in the specified array object, as a `byte`.
`static char`	`getChar(Object array, int index)` Returns the value of the indexed component in the specified array object, as a `char`.
`static double`	`getDouble(Object array, int index)` Returns the value of the indexed component in the specified array object, as a `double`.
`static float`	`getFloat(Object array, int index)` Returns the value of the indexed component in the specified array object, as a `float`.
`static int`	`getInt(Object array, int index)` Returns the value of the indexed component in the specified array object, as an `int`.
`static int`	`getLength(Object array)` Returns the length of the specified array object, as an `int`.
`static long`	`getLong(Object array, int index)` Returns the value of the indexed component in the specified array object, as a `long`.
`static short`	`getShort(Object array, int index)` Returns the value of the indexed component in the specified array object, as a `short`.
`static Object`	`newInstance(Class<?> componentType, int length)` Creates a new array with the specified component type and length.
`static Object`	`newInstance(Class<?> componentType, int... dimensions)` Creates a new array with the specified component type and dimensions.
`static void`	`set(Object array, int index, Object value)` Sets the value of the indexed component of the specified array object to the specified new value.
`static void`	`setBoolean(Object array, int index, boolean z)` Sets the value of the indexed component of the specified array object to the specified `boolean` value.
`static void`	`setByte(Object array, int index, byte b)` Sets the value of the indexed component of the specified array object to the specified `byte` value.
`static void`	`setChar(Object array, int index, char c)` Sets the value of the indexed component of the specified array object to the specified `char` value.
`static void`	`setDouble(Object array, int index, double d)` Sets the value of the indexed component of the specified array object to the specified `double` value.
`static void`	`setFloat(Object array, int index, float f)` Sets the value of the indexed component of the specified array object to the specified `float` value.
`static void`	`setInt(Object array, int index, int i)` Sets the value of the indexed component of the specified array object to the specified `int` value.
`static void`	`setLong(Object array, int index, long l)` Sets the value of the indexed component of the specified array object to the specified `long` value.
`static void`	`setShort(Object array, int index, short s)` Sets the value of the indexed component of the specified array object to the specified `short` value.

Inherited methods

From class java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Public methods

get

public static Object get (Object array, 
                int index)

Returns the value of the indexed component in the specified array object. The value is automatically wrapped in an object if it has a primitive type.

Parameters
`array`	`Object`: the array
`index`	`int`: the index

Returns
`Object`	the (possibly wrapped) value of the indexed component in the specified array

Throws
`ArrayIndexOutOfBoundsException`	If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
`IllegalArgumentException`	If the specified object is not an array
`NullPointerException`	If the specified object is null

getBoolean

public static boolean getBoolean (Object array, 
                int index)

Returns the value of the indexed component in the specified array object, as a boolean.

Parameters
`array`	`Object`: the array
`index`	`int`: the index

Returns
`boolean`	the value of the indexed component in the specified array

Throws
`ArrayIndexOutOfBoundsException`	If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
`IllegalArgumentException`	If the specified object is not an array, or if the indexed element cannot be converted to the return type by an identity or widening conversion
`NullPointerException`	If the specified object is null

getByte

public static byte getByte (Object array, 
                int index)

Returns the value of the indexed component in the specified array object, as a byte.

Parameters
`array`	`Object`: the array
`index`	`int`: the index

Returns
`byte`	the value of the indexed component in the specified array

Throws
`ArrayIndexOutOfBoundsException`	If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
`IllegalArgumentException`	If the specified object is not an array, or if the indexed element cannot be converted to the return type by an identity or widening conversion
`NullPointerException`	If the specified object is null

getChar

public static char getChar (Object array, 
                int index)

Returns the value of the indexed component in the specified array object, as a char.

Parameters
`array`	`Object`: the array
`index`	`int`: the index

Returns
`char`	the value of the indexed component in the specified array

Throws
`ArrayIndexOutOfBoundsException`	If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
`IllegalArgumentException`	If the specified object is not an array, or if the indexed element cannot be converted to the return type by an identity or widening conversion
`NullPointerException`	If the specified object is null

getDouble

public static double getDouble (Object array, 
                int index)

Returns the value of the indexed component in the specified array object, as a double.

Parameters
`array`	`Object`: the array
`index`	`int`: the index

Returns
`double`	the value of the indexed component in the specified array

Throws
`ArrayIndexOutOfBoundsException`	If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
`IllegalArgumentException`	If the specified object is not an array, or if the indexed element cannot be converted to the return type by an identity or widening conversion
`NullPointerException`	If the specified object is null

getFloat

public static float getFloat (Object array, 
                int index)

Returns the value of the indexed component in the specified array object, as a float.

Parameters
`array`	`Object`: the array
`index`	`int`: the index

Returns
`float`	the value of the indexed component in the specified array

Throws
`ArrayIndexOutOfBoundsException`	If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
`IllegalArgumentException`	If the specified object is not an array, or if the indexed element cannot be converted to the return type by an identity or widening conversion
`NullPointerException`	If the specified object is null

getInt

public static int getInt (Object array, 
                int index)

Returns the value of the indexed component in the specified array object, as an int.

Parameters
`array`	`Object`: the array
`index`	`int`: the index

Returns
`int`	the value of the indexed component in the specified array

Throws
`ArrayIndexOutOfBoundsException`	If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
`IllegalArgumentException`	If the specified object is not an array, or if the indexed element cannot be converted to the return type by an identity or widening conversion
`NullPointerException`	If the specified object is null

getLength

public static int getLength (Object array)

Returns the length of the specified array object, as an int.

Parameters
`array`	`Object`: the array

Returns
`int`	the length of the array

Throws
`IllegalArgumentException`	if the object argument is not an array

getLong

public static long getLong (Object array, 
                int index)

Returns the value of the indexed component in the specified array object, as a long.

Parameters
`array`	`Object`: the array
`index`	`int`: the index

Returns
`long`	the value of the indexed component in the specified array

Throws
`ArrayIndexOutOfBoundsException`	If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
`IllegalArgumentException`	If the specified object is not an array, or if the indexed element cannot be converted to the return type by an identity or widening conversion
`NullPointerException`	If the specified object is null

getShort

public static short getShort (Object array, 
                int index)

Returns the value of the indexed component in the specified array object, as a short.

Parameters
`array`	`Object`: the array
`index`	`int`: the index

Returns
`short`	the value of the indexed component in the specified array

Throws
`ArrayIndexOutOfBoundsException`	If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
`IllegalArgumentException`	If the specified object is not an array, or if the indexed element cannot be converted to the return type by an identity or widening conversion
`NullPointerException`	If the specified object is null

newInstance

public static Object newInstance (Class<?> componentType, 
                int length)

Creates a new array with the specified component type and length. Invoking this method is equivalent to creating an array as follows:

 int[] x = {length};
 Array.newInstance(componentType, x);

The number of dimensions of the new array must not exceed 255.

Parameters
`componentType`	`Class`: the `Class` object representing the component type of the new array
`length`	`int`: the length of the new array

Returns
`Object`	the new array

Throws
`IllegalArgumentException`	if componentType is `Void.TYPE` or if the number of dimensions of the requested array instance exceed 255.
`NegativeArraySizeException`	if the specified `length` is negative
`NullPointerException`	if the specified `componentType` parameter is null

newInstance

public static Object newInstance (Class<?> componentType, 
                int... dimensions)

Creates a new array with the specified component type and dimensions. If componentType represents a non-array class or interface, the new array has dimensions.length dimensions and componentType as its component type. If componentType represents an array class, the number of dimensions of the new array is equal to the sum of dimensions.length and the number of dimensions of componentType. In this case, the component type of the new array is the component type of componentType.

The number of dimensions of the new array must not exceed 255.

Parameters
`componentType`	`Class`: the `Class` object representing the component type of the new array
`dimensions`	`int`: an array of `int` representing the dimensions of the new array

Returns
`Object`	the new array

Throws
`IllegalArgumentException`	if the specified `dimensions` argument is a zero-dimensional array, if componentType is `Void.TYPE`, or if the number of dimensions of the requested array instance exceed 255.
`NegativeArraySizeException`	if any of the components in the specified `dimensions` argument is negative.
`NullPointerException`	if the specified `componentType` argument is null

set

public static void set (Object array, 
                int index, 
                Object value)

Sets the value of the indexed component of the specified array object to the specified new value. The new value is first automatically unwrapped if the array has a primitive component type.

Parameters
`array`	`Object`: the array
`index`	`int`: the index into the array
`value`	`Object`: the new value of the indexed component

Throws
`ArrayIndexOutOfBoundsException`	If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
`IllegalArgumentException`	If the specified object argument is not an array, or if the array component type is primitive and an unwrapping conversion fails
`NullPointerException`	If the specified object argument is null

setBoolean

public static void setBoolean (Object array, 
                int index, 
                boolean z)

Sets the value of the indexed component of the specified array object to the specified boolean value.

Parameters
`array`	`Object`: the array
`index`	`int`: the index into the array
`z`	`boolean`: the new value of the indexed component

Throws
`ArrayIndexOutOfBoundsException`	If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
`IllegalArgumentException`	If the specified object argument is not an array, or if the specified value cannot be converted to the underlying array's component type by an identity or a primitive widening conversion
`NullPointerException`	If the specified object argument is null

setByte

public static void setByte (Object array, 
                int index, 
                byte b)

Sets the value of the indexed component of the specified array object to the specified byte value.

Parameters
`array`	`Object`: the array
`index`	`int`: the index into the array
`b`	`byte`: the new value of the indexed component

Throws
`ArrayIndexOutOfBoundsException`	If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
`IllegalArgumentException`	If the specified object argument is not an array, or if the specified value cannot be converted to the underlying array's component type by an identity or a primitive widening conversion
`NullPointerException`	If the specified object argument is null

setChar

public static void setChar (Object array, 
                int index, 
                char c)

Sets the value of the indexed component of the specified array object to the specified char value.

Parameters
`array`	`Object`: the array
`index`	`int`: the index into the array
`c`	`char`: the new value of the indexed component

Throws
`ArrayIndexOutOfBoundsException`	If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
`IllegalArgumentException`	If the specified object argument is not an array, or if the specified value cannot be converted to the underlying array's component type by an identity or a primitive widening conversion
`NullPointerException`	If the specified object argument is null

setDouble

public static void setDouble (Object array, 
                int index, 
                double d)

Sets the value of the indexed component of the specified array object to the specified double value.

Parameters
`array`	`Object`: the array
`index`	`int`: the index into the array
`d`	`double`: the new value of the indexed component

Throws
`ArrayIndexOutOfBoundsException`	If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
`IllegalArgumentException`	If the specified object argument is not an array, or if the specified value cannot be converted to the underlying array's component type by an identity or a primitive widening conversion
`NullPointerException`	If the specified object argument is null

setFloat

public static void setFloat (Object array, 
                int index, 
                float f)

Sets the value of the indexed component of the specified array object to the specified float value.

Parameters
`array`	`Object`: the array
`index`	`int`: the index into the array
`f`	`float`: the new value of the indexed component

Throws
`ArrayIndexOutOfBoundsException`	If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
`IllegalArgumentException`	If the specified object argument is not an array, or if the specified value cannot be converted to the underlying array's component type by an identity or a primitive widening conversion
`NullPointerException`	If the specified object argument is null

setInt

public static void setInt (Object array, 
                int index, 
                int i)

Sets the value of the indexed component of the specified array object to the specified int value.

Parameters
`array`	`Object`: the array
`index`	`int`: the index into the array
`i`	`int`: the new value of the indexed component

Throws
`ArrayIndexOutOfBoundsException`	If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
`IllegalArgumentException`	If the specified object argument is not an array, or if the specified value cannot be converted to the underlying array's component type by an identity or a primitive widening conversion
`NullPointerException`	If the specified object argument is null

setLong

public static void setLong (Object array, 
                int index, 
                long l)

Sets the value of the indexed component of the specified array object to the specified long value.

Parameters
`array`	`Object`: the array
`index`	`int`: the index into the array
`l`	`long`: the new value of the indexed component

Throws
`ArrayIndexOutOfBoundsException`	If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
`IllegalArgumentException`	If the specified object argument is not an array, or if the specified value cannot be converted to the underlying array's component type by an identity or a primitive widening conversion
`NullPointerException`	If the specified object argument is null

setShort

public static void setShort (Object array, 
                int index, 
                short s)

Sets the value of the indexed component of the specified array object to the specified short value.

Parameters
`array`	`Object`: the array
`index`	`int`: the index into the array
`s`	`short`: the new value of the indexed component

Throws
`ArrayIndexOutOfBoundsException`	If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
`IllegalArgumentException`	If the specified object argument is not an array, or if the specified value cannot be converted to the underlying array's component type by an identity or a primitive widening conversion
`NullPointerException`	If the specified object argument is null