The array_walk function iterates through an array of elements and passes each element’s key and value to a user-defined function. The keys and values of the array are the parameters of the user-defined function.
We can change the value in the user-defined function by passing the first parameter ($value) as reference (&$value).
What is the syntax of the array_walk function in PHP?
array_walk(array, myfunction, parameter...)
| Parameters | Details |
|---|---|
| array | The array to walking through – Required |
| my_function | The user-defined function for array keys and values – Required |
| parameter,… | Defines the parameters for the user-defined function – Optional |
Examples of array_walk function
Example 1. Example of array_walk with parameter.
<?php
function my_function($value,$key,$param)
{
echo "$key $param $value";
}
$arr=array("a"=>"R","b"=>"G","c"=>"B");
array_walk($arr,"my_function","contains value");
?>Example 2. Change the array element value within the array_walk user-defined function.
<?php
function my_function(&$value,$key)
{
$value="Red";
}
$arr=array("a"=>"R","b"=>"G","c"=>"B");
array_walk($arr,"my_function");
print_r($arr);
?>
