Overview | Package | Class | Use | Tree | Deprecated | Index | Help
| Java™ Platform Standard Ed. 6
PREV CLASS NEXT CLASS | FRAMES NO FRAMES
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD

## java.lang.reflect
Class Array

    java.lang.Object
      java.lang.reflect.Array

    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.

Method Summary
`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... dimensions)` Creates a new array with the specified component type and dimensions.
`static Object` | `newInstance(Class<?> componentType, int length)` Creates a new array with the specified component type and length.
`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.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Method Detail

### newInstance

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

  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);

  Parameters:
    `componentType` - the `Class` object representing the component type of the new array
    `length` - the length of the new array
  Returns:
    the new array
  Throws:
    `NullPointerException` - if the specified `componentType` parameter is null
    `IllegalArgumentException` - if componentType is `Void.TYPE`
    `NegativeArraySizeException` - if the specified `length` is negative

### newInstance

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

  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 the number of array dimensions supported by the implementation (typically 255).

  Parameters:
    `componentType` - the `Class` object representing the component type of the new array
    `dimensions` - an array of `int` representing the dimensions of the new array
  Returns:
    the new array
  Throws:
    `NullPointerException` - if the specified `componentType` argument is null
    `IllegalArgumentException` - if the specified `dimensions` argument is a zero-dimensional array, or if the number of requested dimensions exceeds the limit on the number of array dimensions supported by the implementation (typically 255), or if componentType is `Void.TYPE`.
    `NegativeArraySizeException` - if any of the components in the specified `dimensions` argument is negative.

### getLength

    public static int getLength(Object array)
                         throws IllegalArgumentException

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

  Parameters:
    `array` - the array
  Returns:
    the length of the array
  Throws:
    `IllegalArgumentException` - if the object argument is not an array

### get

    public static Object get(Object array,
                             int index)
                      throws IllegalArgumentException,
                             ArrayIndexOutOfBoundsException

  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` - the array
    `index` - the index
  Returns:
    the (possibly wrapped) value of the indexed component in the specified array
  Throws:
    `NullPointerException` - If the specified object is null
    `IllegalArgumentException` - If the specified object is not an array
    `ArrayIndexOutOfBoundsException` - If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array

### getBoolean

    public static boolean getBoolean(Object array,
                                     int index)
                              throws IllegalArgumentException,
                                     ArrayIndexOutOfBoundsException

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

  Parameters:
    `array` - the array
    `index` - the index
  Returns:
    the value of the indexed component in the specified array
  Throws:
    `NullPointerException` - If the specified object is null
    `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
    `ArrayIndexOutOfBoundsException` - If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
  See Also:
    `get(java.lang.Object, int)`

### getByte

    public static byte getByte(Object array,
                               int index)
                        throws IllegalArgumentException,
                               ArrayIndexOutOfBoundsException

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

  Parameters:
    `array` - the array
    `index` - the index
  Returns:
    the value of the indexed component in the specified array
  Throws:
    `NullPointerException` - If the specified object is null
    `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
    `ArrayIndexOutOfBoundsException` - If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
  See Also:
    `get(java.lang.Object, int)`

### getChar

    public static char getChar(Object array,
                               int index)
                        throws IllegalArgumentException,
                               ArrayIndexOutOfBoundsException

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

  Parameters:
    `array` - the array
    `index` - the index
  Returns:
    the value of the indexed component in the specified array
  Throws:
    `NullPointerException` - If the specified object is null
    `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
    `ArrayIndexOutOfBoundsException` - If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
  See Also:
    `get(java.lang.Object, int)`

### getShort

    public static short getShort(Object array,
                                 int index)
                          throws IllegalArgumentException,
                                 ArrayIndexOutOfBoundsException

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

  Parameters:
    `array` - the array
    `index` - the index
  Returns:
    the value of the indexed component in the specified array
  Throws:
    `NullPointerException` - If the specified object is null
    `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
    `ArrayIndexOutOfBoundsException` - If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
  See Also:
    `get(java.lang.Object, int)`

### getInt

    public static int getInt(Object array,
                             int index)
                      throws IllegalArgumentException,
                             ArrayIndexOutOfBoundsException

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

  Parameters:
    `array` - the array
    `index` - the index
  Returns:
    the value of the indexed component in the specified array
  Throws:
    `NullPointerException` - If the specified object is null
    `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
    `ArrayIndexOutOfBoundsException` - If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
  See Also:
    `get(java.lang.Object, int)`

### getLong

    public static long getLong(Object array,
                               int index)
                        throws IllegalArgumentException,
                               ArrayIndexOutOfBoundsException

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

  Parameters:
    `array` - the array
    `index` - the index
  Returns:
    the value of the indexed component in the specified array
  Throws:
    `NullPointerException` - If the specified object is null
    `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
    `ArrayIndexOutOfBoundsException` - If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
  See Also:
    `get(java.lang.Object, int)`

### getFloat

    public static float getFloat(Object array,
                                 int index)
                          throws IllegalArgumentException,
                                 ArrayIndexOutOfBoundsException

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

  Parameters:
    `array` - the array
    `index` - the index
  Returns:
    the value of the indexed component in the specified array
  Throws:
    `NullPointerException` - If the specified object is null
    `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
    `ArrayIndexOutOfBoundsException` - If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
  See Also:
    `get(java.lang.Object, int)`

### getDouble

    public static double getDouble(Object array,
                                   int index)
                            throws IllegalArgumentException,
                                   ArrayIndexOutOfBoundsException

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

  Parameters:
    `array` - the array
    `index` - the index
  Returns:
    the value of the indexed component in the specified array
  Throws:
    `NullPointerException` - If the specified object is null
    `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
    `ArrayIndexOutOfBoundsException` - If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
  See Also:
    `get(java.lang.Object, int)`

### set

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

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

### setBoolean

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

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

  Parameters:
    `array` - the array
    `index` - the index into the array
    `z` - the new value of the indexed component
  Throws:
    `NullPointerException` - If the specified object argument is null
    `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
    `ArrayIndexOutOfBoundsException` - If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
  See Also:
    `set(java.lang.Object, int, java.lang.Object)`

### setByte

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

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

  Parameters:
    `array` - the array
    `index` - the index into the array
    `b` - the new value of the indexed component
  Throws:
    `NullPointerException` - If the specified object argument is null
    `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
    `ArrayIndexOutOfBoundsException` - If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
  See Also:
    `set(java.lang.Object, int, java.lang.Object)`

### setChar

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

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

  Parameters:
    `array` - the array
    `index` - the index into the array
    `c` - the new value of the indexed component
  Throws:
    `NullPointerException` - If the specified object argument is null
    `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
    `ArrayIndexOutOfBoundsException` - If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
  See Also:
    `set(java.lang.Object, int, java.lang.Object)`

### setShort

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

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

  Parameters:
    `array` - the array
    `index` - the index into the array
    `s` - the new value of the indexed component
  Throws:
    `NullPointerException` - If the specified object argument is null
    `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
    `ArrayIndexOutOfBoundsException` - If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
  See Also:
    `set(java.lang.Object, int, java.lang.Object)`

### setInt

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

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

  Parameters:
    `array` - the array
    `index` - the index into the array
    `i` - the new value of the indexed component
  Throws:
    `NullPointerException` - If the specified object argument is null
    `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
    `ArrayIndexOutOfBoundsException` - If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
  See Also:
    `set(java.lang.Object, int, java.lang.Object)`

### setLong

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

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

  Parameters:
    `array` - the array
    `index` - the index into the array
    `l` - the new value of the indexed component
  Throws:
    `NullPointerException` - If the specified object argument is null
    `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
    `ArrayIndexOutOfBoundsException` - If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
  See Also:
    `set(java.lang.Object, int, java.lang.Object)`

### setFloat

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

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

  Parameters:
    `array` - the array
    `index` - the index into the array
    `f` - the new value of the indexed component
  Throws:
    `NullPointerException` - If the specified object argument is null
    `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
    `ArrayIndexOutOfBoundsException` - If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
  See Also:
    `set(java.lang.Object, int, java.lang.Object)`

### setDouble

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

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

  Parameters:
    `array` - the array
    `index` - the index into the array
    `d` - the new value of the indexed component
  Throws:
    `NullPointerException` - If the specified object argument is null
    `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
    `ArrayIndexOutOfBoundsException` - If the specified `index` argument is negative, or if it is greater than or equal to the length of the specified array
  See Also:
    `set(java.lang.Object, int, java.lang.Object)`

Overview | Package | Class | Use | Tree | Deprecated | Index | Help
| Java™ Platform Standard Ed. 6
PREV CLASS NEXT CLASS | FRAMES NO FRAMES
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD

Submit a bug or feature
For further API reference and developer documentation, see Java SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

Copyright © 1993, 2011, Oracle and/or its affiliates. All rights reserved.