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 | |
static boolean |
getBoolean(Object array, int index)
Returns the value of the indexed component in the specified
array object, as a
boolean . |
static byte | |
static char | |
static double | |
static float | |
static int | |
static int | |
static long | |
static 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 | |
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 | |
static void | |
static void | |
static void | |
static void | |
static void | |
static void |
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);
The number of dimensions of the new array must not exceed 255.
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 or if the number of dimensions of the requested array
instance exceed 255. |
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 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, 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.
|
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 |
See Also
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 |
See Also
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 |
See Also
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 |
See Also
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 |
See Also
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 |
See Also
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 |
See Also
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 |