array_slice()

5th June 2020

Programming Language

PHP [Versions: 4, 5, 7]

Syntax

Typical Usage

Setting a limit and/or an offset on an array to extract a slice of the array. Works similar to an SQL statement that limits and offsets the data pulled from a database.

Accepted Parameters

array (array) (Required): The array you wish to slice.
offset (integer) (Required): If the offset is non-negative, the sequence will start at that offset in the array. If the offset is negative, the sequence will start that far from the end of the array.
limit (integer) (Required): If length is given and is positive, then the sequence will have up to that many elements in it.
preserve_keys (boolean) (Optional, Default = false): If preserve_keys is false or left blank, arrays with integer keys will be reset to the default 0, 1, 2 etc…. String keys will always remain intact regardless of this setting.

Notes

The offset parameter refers to the position in the array, not the key.
array_slice() will reorder and reset arrays with integer indices by default. To override this, set preserve_keys to true.

Examples of array_slice()

Example 1

<?php
$products = array (
    'spoon',
    'fork',
    'knife',
    'plate',
    'cup',
    'jug'
);

array_slice ( $products, 2, 4 );

Output

Array (
   [0] => fork
   [1] => knife
   [2] => plate
   [3] => cup
)

Example 2

<?php
$products = array (
    'spoon',
    'fork',
    'knife',
    'plate',
    'cup',
    'jug'
);

array_slice ( $products, 1, 4, true );

Output

Array (
   [1] => fork
   [2] => knife
   [3] => plate
   [4] => cup
)

Example 3 (Associative Array)

<?php
$products = array (
    'kitchenware' => array(
       'spoon',
       'fork',
       'knife',
       'plate',
       'cup',
       'jug'
    ),
    'tools' => array(
       'spanner',
       'screwdriver',
       'hammer',
       'spade'
   ),
   'bedding' => array(
       'pillow',
       'blanket',
       'duvet'
   ),
   'tech' => array(
       'monitor',
       'usb',
       'tv'
   ),
);

array_slice ( $products, 1, 2 );

Output

Array (
   [tools] => Array (
                    spanner
                    screwdriver
                    hammer
                   spade
     )
   [bedding] => Array (
                   pillow
                   blanket
                   duvet
    )
)

The above will output the same whether the third parameter (preserve_keys) is true or false.