PHP array_walk() Function
Example
Run each array element in a user-defined function:
<?php
function myfunction($value,$key)
{
echo "The key $key has the value $value<br>";
}
$a=array("a"=>"red","b"=>"green","c"=>"blue");
array_walk($a,"myfunction");
?>
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Definition and Usage
The array_walk() function runs each array element in a user-defined function. The array's keys and values are parameters in the function.
Note: You can change an array element's value in the user-defined function by specifying the first parameter as a reference: &$value (See Example 2).
Tip: To work with deeper arrays (an array inside an array), use the array_walk_recursive() function.
Syntax
array_walk(array, myfunction, parameter...)
Parameter Values
| Parameter | Description |
|---|---|
| array | Required. Specifying an array |
| myfunction | Required. The name of the user-defined function |
| parameter,... | Optional. Specifies a parameter to the user-defined function. You can assign one parameter to the function, or as many as you like |
Technical Details
| Return Value: | Returns TRUE on success or FALSE on failure |
|---|---|
| PHP Version: | 4+ |
More Examples
Example 1
With a parameter:
<?php
function myfunction($value,$key,$p)
{
echo "$key $p $value<br>";
}
$a=array("a"=>"red","b"=>"green","c"=>"blue");
array_walk($a,"myfunction","has the value");
?>
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Example 2
Change an array element's value. (Notice the &$value)
<?php
function myfunction(&$value,$key)
{
$value="yellow";
}
$a=array("a"=>"red","b"=>"green","c"=>"blue");
array_walk($a,"myfunction");
print_r($a);
?>
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❮ PHP Array Reference
