PHP array_walk()Functions
Complete PHP Array Reference Manual
Example
Apply a user-defined function to each element in the array:
<?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");
?>
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");
?>
Run Example »
Definition and Usage
The array_walk() function applies a user-defined function to each element in the array. In the function, the array's key name and key value are parameters.
Note:You can change the value of array elements by specifying the first parameter of the user-defined function as a reference: &$value (see Example 2).
Tip:To operate on deeper arrays (an array containing another array), use thearray_walk_recursive()function.
Syntax
array_walk(array,myfunction,parameter...)
| Parameter | Description |
|---|---|
| array | Required. Specifies the array. |
| myfunction | Required. The name of the user-defined function. |
| parameter,... | Optional. Specifies the parameters of the user-defined function. You can set one or more parameters for the function. |
Technical Details
| Return value: | Returns TRUE on success, or FALSE otherwise. |
|---|---|
| PHP Version: | 4+ |
More Examples
Example 1
With one parameter:
<?php
function myfunction($value,$key,$p)
{
echo "$key $p $value<br>";
}
$a=array("a"=>"red","b"=>"green","c"=>"blue");
array_walk($a,"myfunction","has the value");
?>
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 the value of array elements (note the &$value):
<?php
function myfunction(&$value,$key)
{
$value="yellow";
}
$a=array("a"=>"red","b"=>"green","c"=>"blue");
array_walk($a,"myfunction");
print_r($a);
?>
function myfunction(&$value,$key)
{
$value="yellow";
}
$a=array("a"=>"red","b"=>"green","c"=>"blue");
array_walk($a,"myfunction");
print_r($a);
?>
Run Example »
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