array_walk

bool array_walk(array array, string func, mixed userdata) 

Applies a specified function to each element of an array, along with optional input.

Returns:

TRUE on success; NULL if given invalid arguments

Description:

Traverses the given array and passes each element into the given function in turn. The function given as func is called once for every element of array . The function named by func can accept up to three parameters for each element:

param1	Key of the current element
param2	Value of the current element
param3	Value of the userdata argument to array_walk(), if given

If the function named by func accepts more than three parameters, it generates a warning, unless that warning is suppressed either by using the error_reporting() function or by prepending the @ error-suppression operator to the array_walk() call.

array_walk() doesn't directly alter the elements of array unless you explicitly tell it to do so, by writing the function named by func to take its first parameter by reference.

Version:

PHP 3 since 3.0.3, PHP 4

Example:

Apply a callback function to each element of an array

function output_element($a) {
print("Element value: $a\n"); 
} 
$arr1 = array("alpha", "baker", "charlie", "delta"); 
array_walk($arr1, "output_element"); 

Output: 
Element value: alpha 
Element value: baker 
Element value: charlie 
Element value: delta