PHP Manual
PrevNext

array_merge

(PHP 4 )

array_merge -- Merge two or more arrays

Description

array array_merge ( array array1, array array2 [, array ...])

array_merge() merges the elements of two or more arrays together so that the values of one are appended to the end of the previous one. It returns the resulting array.

If the input arrays have the same string keys, then the later value for that key will overwrite the previous one. If, however, the arrays contain numeric keys, the later value will not overwrite the original value, but will be appended.

Example 1. array_merge() example

<?php
$array1 = array("color" => "red", 2, 4);
$array2 = array("a", "b", "color" => "green", "shape" => "trapezoid", 4);
$result = array_merge($array1, $array2);
print_r($result);
?>

The $result is: 

Array
(
    [color] => green
    [0] => 2
    [1] => 4
    [2] => a
    [3] => b
    [shape] => trapezoid
    [4] => 4
)

Example 2. Simple array_merge() example

<?php
$array1 = array();
$array2 = array(1 => "data");
$result = array_merge($array1, $array2);
?>

Don't forget that numeric keys will be renumbered! 

Array
(
    [0] => data
)

If you want to completely preserve the arrays and just want to append them to each other, use the + operator: 

<?php
$array1 = array();
$array2 = array(1 => "data");
$result = $array1 + $array2;
?>

The numeric key will be preserved and thus the association remains. 

Array
(
    [1] => data
)

Note: Shared keys will be overwritten on a first-come first-served basis.

See also array_merge_recursive() and array_combine().

PrevHomeNext
array_merge_recursiveUparray_multisort