note 41958 added to function.array-walk

From: Date: Tue, 27 Apr 2004 18:15:46 +0000
Subject: note 41958 added to function.array-walk
Groups: php.notes 
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burrowballer69 at hotmail dot com: Ok, I see two problems with your example: 1. you call "echo array_walk()", which is faulty by design (at least from what I think your code is trying to do, because array_walk() returns a bool which indicates success or failure of the "walk", not what is "return"d from the callback function. Instead, how about: function function_name($value, $key) { echo $value; } foreach($array as $key => $value) { my_array_walk($value, 'function_name'); } 2. by doing the foreach() on a single dimensional array, the $value variable in each iteration of the loop (in your example at least) is just a string ("goats" or "milk"), and so passing a string value into array_walk() when its expecting an array, would expectedly give unexpected results. ********************************* However, was your intention to have each string treated as an array of characters? PHP gives the {} operators, which allow you to reference the single character at a position in the string's "array" of characters. i don't think that array_walk() by default would use the {}, it probably assumes a traditional array and uses [] appropriately. You could write your own version of array_walk for a string using the {} operators though, and i bet it would work the same. maybe, use a wrapper, which for your example might look something like this: function string_walk($mystring,$callback,$userdata = null) { for ($i=0; $i<strlen($mystring); $i++) { call_user_func_array($callback,array($mystring{$i},$i,$userdata)); } } function my_array_walk($myarray,$callback,$userdata = null) { if (is_string($myarray)) string_walk($myarray,$callback,$userdata); else array_walk($myarray,$callback,$userdata); } $thearray = array('goat','milk'); function function_name($value, $key) { echo $value; // notice this is changed to resolve #1 } foreach($thearray as $key => $value) { my_array_walk($value, 'function_name'); // again, above line changed to resolve #1 } ---- Manual Page -- http://www.php.net/manual/en/function.array-walk.php Edit -- http://master.php.net/manage/user-notes.php?action=edit+41958 Delete -- http://master.php.net/manage/user-notes.php?action=delete+41958&report=yes Reject -- http://master.php.net/manage/user-notes.php?action=reject+41958&report=yes Search -- http://master.php.net/manage/user-notes.php

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