Class Array
java.lang.reflect
java.lang.Object
  java.lang.reflect.Array
final public 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.

Author:
Nakul Saraiya
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 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.
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:
NegativeArraySizeException - if the specified length is negative
NullPointerException - if the specified componentType parameter is null
IllegalArgumentException - if componentType is Void.TYPE
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:
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.
NullPointerException - if the specified componentType argument is null
getLength
public static native 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 native 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:
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
NullPointerException - If the specified object is null
getBoolean
public static native 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:
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
NullPointerException - If the specified object is null
See Also:
getByte
public static native 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:
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
NullPointerException - If the specified object is null
See Also:
getChar
public static native 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:
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
NullPointerException - If the specified object is null
See Also:
getShort
public static native 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:
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
NullPointerException - If the specified object is null
See Also:
getInt
public static native 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:
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
NullPointerException - If the specified object is null
See Also:
getLong
public static native 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:
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
NullPointerException - If the specified object is null
See Also:
getFloat
public static native 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:
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
NullPointerException - If the specified object is null
See Also:
getDouble
public static native 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:
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
NullPointerException - If the specified object is null
See Also:
set
public static native 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:
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
NullPointerException - If the specified object argument is null
setBoolean
public static native 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:
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
NullPointerException - If the specified object argument is null
See Also:
setByte
public static native 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:
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
NullPointerException - If the specified object argument is null
See Also:
setChar
public static native 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:
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
NullPointerException - If the specified object argument is null
See Also:
setShort
public static native 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:
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
NullPointerException - If the specified object argument is null
See Also:
setInt
public static native 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:
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
NullPointerException - If the specified object argument is null
See Also:
setLong
public static native 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:
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
NullPointerException - If the specified object argument is null
See Also:
setFloat
public static native 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:
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
NullPointerException - If the specified object argument is null
See Also:
setDouble
public static native 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:
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
NullPointerException - If the specified object argument is null
See Also:
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