PHP array_merge() Function
Topic: PHP Array ReferencePrev|Next
Description
The array_merge() function merge one or more arrays into one array.
This function merges the elements of one or more arrays together in such a way that the values of one are appended to the end of the previous one. It returns a new array with merged elements.
The following table summarizes the technical details of this function.
| Return Value: | Returns the merged array. |
|---|---|
| Changelog: | Since PHP 5.0, this function only accept parameters of type array. |
| Version: | PHP 4+ |
Syntax
The basic syntax of the array_merge() function is given with:
The following example shows the array_merge() function in action.
Example
Run this code »<?php
// Sample arrays
$array1 = array("red", "green", "blue");
$array2 = array("apple", "banana");
// Merging the two indexed array
$result = array_merge($array1, $array2);
print_r($result);
?>Similarly, you can merge two or more associative arrays as shown in the example below:
Example
Run this code »<?php
// Sample arrays
$array1 = array("a" => "apple", "b" => "ball", "c" => "cat");
$array2 = array("x" => "xylophone", "y" => "yacht", "z" => "zebra");
// Merging the two associative arrays
$result = array_merge($array1, $array2);
print_r($result);
?>It is also possible to merge indexed and associative array, as shown here:
Example
Run this code »<?php
// Sample arrays
$array1 = array(4, 6, 12, 18);
$array2 = array("a"=>"apple", "b"=>"ball", "c"=>"cat");
// Merging two indexed arrays
$result = array_merge($array1, $array2);
print_r($result);
?>Parameters
The array_merge() function accepts the following parameters.
| Parameter | Description |
|---|---|
| array1 | Optional. Specifies the first array to merge. |
| array2 | Optional. Specifies the second array to merge. |
| ... | Optional. Specifies more arrays to merge. |
Note: As of PHP version 7.4.0 the array_merge() function can now be called without any parameter. Earlier, at least one parameter has been required.
More Examples
Here're some more examples showing how array_merge() function basically works:
If the input arrays have the same string keys, then the later value for that key will overwrite the previous one, as you can see in the following example:
Example
Run this code »<?php
// Sample arrays
$array1 = array("a"=>"red", "b"=>"green", "c"=>"blue");
$array2 = array("a"=>"apple", "m"=>"mango", "o"=>"orange");
// Merging two associative arrays
$result = array_merge($array1, $array2);
print_r($result);
?>However, if the arrays contain numeric keys, the later value will not overwrite the original value, but will be appended, as demonstrated in the following example:
Example
Run this code »<?php
// Sample arrays
$array1 = array(5, 10, 15, 20);
$array2 = array(10, 30, 50, 80);
// Merging two indexed arrays
$result = array_merge($array1, $array2);
print_r($result);
?>
