php man page for array_walk_recursive

ARRAY_WALK_RECURSIVE(3) 						 1						   ARRAY_WALK_RECURSIVE(3)

array_walk_recursive - Apply a user function recursively to every member of an array

SYNOPSIS
       bool array_walk_recursive NULL (array  &$array, callable  $callback, [mixed  $userdata])

DESCRIPTION
	Applies the user-defined $callback function to each element of the $array. This function will recurse into deeper arrays.

PARAMETERS
	      o $array
		- The input array.

	      o $callback
		- Typically, $callback takes on two parameters. The $array parameter's value being the first, and the key/index second.

	      Note

		      If  $callback  needs to be working with the actual values of the array, specify the first parameter of $callback as a refer-
		     ence. Then, any changes made to those elements will be made in the original array itself.

	      o $userdata
		- If the optional $userdata parameter is supplied, it will be passed as the third parameter to the $callback.

RETURN VALUES
	Returns TRUE on success or FALSE on failure.

EXAMPLES
       Example #1

	      array_walk_recursive(3) example

	      <?php
	      $sweet = array('a' => 'apple', 'b' => 'banana');
	      $fruits = array('sweet' => $sweet, 'sour' => 'lemon');

	      function test_print($item, $key)
	      {
		  echo "$key holds $item
";
	      }

	      array_walk_recursive($fruits, 'test_print');
	      ?>

	      The above example will output:

	      a holds apple
	      b holds banana
	      sour holds lemon

	       You may notice that the key ' sweet' is never displayed. Any key that holds an array will not be passed to the function.

SEE ALSO
       array_walk(3), information about the callback type.

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