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.

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

Inherited Method Summary

Public Methods

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 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

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 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

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 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

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 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

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 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

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 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

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 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

public static int getLength (Object array)

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

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 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

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 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

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);
 

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 TYPE
NegativeArraySizeException if the specified length is negative

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 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 TYPE.
NegativeArraySizeException if any of the components in the specified dimensions argument is negative.

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 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

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

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
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 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

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

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
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 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

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

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
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 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

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

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
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 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

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

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
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 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

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

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
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 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

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

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
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 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

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

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
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 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