PHP array_merge() Function

Example

Merge two arrays into one array:

<?php
$a1=array("red","green");
$a2=array("blue","yellow");
print_r(array_merge($a1,$a2));
?>
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Definition and Usage

The array_merge() function merges one or more arrays into one array.

Tip: You can assign one array to the function, or as many as you like.

Note: If two or more array elements have the same key, the last one overrides the others.

Note: If you assign only one array to the array_merge() function, and the keys are integers, the function returns a new array with integer keys starting at 0 and increases by 1 for each value (See example below).

Tip: The difference between this function and the array_merge_recursive() function is when two or more array elements have the same key. Instead of override the keys, the array_merge_recursive() function makes the value as an array.


Syntax

array_merge(array1, array2, array3, ...)

Parameter Values

Parameter Description
array1 Required. Specifies an array
array2 Optional. Specifies an array
array3,... Optional. Specifies an array


Technical Details

Return Value: Returns the merged array
PHP Version: 4+
Changelog: As of PHP 5.0, this function only accept parameters of type array

More Examples

Example

Merge two associative arrays into one array:

<?php
$a1=array("a"=>"red","b"=>"green");
$a2=array("c"=>"blue","b"=>"yellow");
print_r(array_merge($a1,$a2));
?>
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Example

Using only one array parameter with integer keys:

<?php
$a=array(3=>"red",4=>"green");
print_r(array_merge($a));
?>
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