How to merge two arrays in php

How to merge two arrays in php?

In PHP, you can use the array_merge() function to merge two arrays.

Definition and usage

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

Tip: You can input one or more arrays to the function.

Note: If two or more array elements have the same key name, the last element will overwrite the other elements.

Note: If you input only an array to the array_merge() function, and the keys are integers, the function will return a new array with integer keys, with keys re-indexed starting at 0 ( See Example 1) below.

Tip: The difference between this function and the array_merge_recursive() function is that it handles the case where two or more array elements have the same key name. array_merge_recursive() does not perform key name overwriting, but recursively combines multiple values ​​with the same key name into an array.

Syntax

array_merge(array1,array2,array3...)

Parameters

array1 Required. Specifies an array.

array2 Optional. Specifies an array.

array3 Optional. Specifies an array.

Return value: Return the merged array.

Recommended: "PHP Tutorial"

Example 1

Combine two arrays into one array:

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

Output:

Array ( [0] => red [1] => green [2] => blue [3] => yellow )

Example 2

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));
?>

Output:

Array ( [a] => red [b] => yellow [c] => blue )

Example 3

Use only one array parameter with integer key name:

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

Output:

Array ( [0] => red [1] => green )

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