array_slice

(PHP 4, PHP 5, PHP 7)

array_slice — Extract a slice of the array

Description

array_slice ( array $array , int $offset [, int $length = NULL [, bool $preserve_keys = FALSE ]] ) : array

array_slice() returns the sequence of elements from the array array as specified by the offset and length parameters.

Parameters

array

The input array.

offset

If offset is non-negative, the sequence will start at that offset in the array.

If offset is negative, the sequence will start that far from the end of the array.

Note:

The offset parameter denotes the position in the array, not the key.

length

If length is given and is positive, then the sequence will have up to that many elements in it.

If the array is shorter than the length, then only the available array elements will be present.

If length is given and is negative then the sequence will stop that many elements from the end of the array.

If it is omitted, then the sequence will have everything from offset up until the end of the array.

preserve_keys

Note:

array_slice() will reorder and reset the integer array indices by default. This behaviour can be changed by setting preserve_keys to TRUE. String keys are always preserved, regardless of this parameter.

Return Values

Returns the slice. If the offset is larger than the size of the array, an empty array is returned.

Changelog

Version Description
5.2.4 The default value of the length parameter was changed to NULL. A NULL length now tells the function to use the length of array. Prior to this version, a NULL length was taken to mean a zero length (nothing will be returned).
5.0.2 The optional preserve_keys parameter was added.

Examples

Example #1 array_slice() examples

<?php
$input = array("a", "b", "c", "d", "e");

$output = array_slice($input, 2);      // returns "c", "d", and "e"
$output = array_slice($input, -2, 1);  // returns "d"
$output = array_slice($input, 0, 3);   // returns "a", "b", and "c"

// note the differences in the array keys
print_r(array_slice($input, 2, -1));
print_r(array_slice($input, 2, -1, true));
?>

The above example will output:

Array
(
    [0] => c
    [1] => d
)
Array
(
    [2] => c
    [3] => d
)

Example #2 array_slice() and one-based array

<?php
$input = array(1 => "a", "b", "c", "d", "e");
print_r(array_slice($input, 1, 2));
?>

The above example will output:

Array
(
    [0] => b
    [1] => c
)

Example #3 array_slice() and array with mixed keys

<?php
$ar = array('a'=>'apple', 'b'=>'banana', '42'=>'pear', 'd'=>'orange');
print_r(array_slice($ar, 0, 3));
print_r(array_slice($ar, 0, 3, true));
?>

The above example will output:

Array
(
    [a] => apple
    [b] => banana
    [0] => pear
)
Array
(
    [a] => apple
    [b] => banana
    [42] => pear
)

See Also