note 38621 modified in function.str-replace by aidan

If both the search and replace params are arrays, str_replace() will apply the substitutions incrementally, it is, it will try the first substitution, then the second using the result from the first one, and so on. It may be OK, or it may be a problem if you only want to change the original text. For example, consider this code: <?php $search = array("one", "two", "three"); $replace = array("two", "three", "one"); $subject = "one two three"; echo str_replace($search, $replace, $subject). "<br>"; // echoes "one one one" ?> This function makes the substitutions only to the original text. <?php /** * same as str_replace (array, array, string), but changing only the text in the * original string * $search and $replace are arrays of strings, $subject is a string */ function str_replace_clean($search, $replace, $subject) { if (!is_array($search) or !is_array($replace) or !is_string($subject)) return $subject; while (count($search)) { // get current terms, reduce the arrays for the next iteration $search_text = array_shift($search); $replace_text = array_shift($replace); // check if the substring is present $pos = strpos($subject, $search_text); if (is_int($pos)) { // match found - break in pieces $pieces = explode($search_text, $subject); if (count($search)) { // only if there are more substitutions to do // make next substitutions in every piece of text between matches foreach ($pieces as $k => $v) { if (strlen($v)) $pieces[$k] = str_replace_clean($search, $replace, $v); } } $subject = join($replace_text, $pieces); break; } } return $subject; } ?> To test: <?php echo str_replace_clean($search, $replace, $subject); // echoes "two three one" ?> -- Xavier --was-- If both the search and replace params are arrays, str_replace() will apply the substitutions incrementally, it is, it will try the first substitution, then the second using the result from the first one, and so on. It may be OK, or it may be a problem if you only want to change the original text. For example, consider this code: $search = array("one", "two", "three"); $replace = array("two", "three", "one"); $subject = "one two three"; echo str_replace($search, $replace, $subject). "<br>"; // echoes "one one one" This function makes the substitutions only to the original text. /** * same as str_replace (array, array, string), but changing only the text in the * original string * $search and $replace are arrays of strings, $subject is a string */ function str_replace_clean($search, $replace, $subject) { if (!is_array($search) or !is_array($replace) or !is_string($subject)) return $subject; while (count($search)) { // get current terms, reduce the arrays for the next iteration $search_text = array_shift($search); $replace_text = array_shift($replace); // check if the substring is present $pos = strpos($subject, $search_text); if (is_int($pos)) { // match found - break in pieces $pieces = explode($search_text, $subject); if (count($search)) { // only if there are more substitutions to do // make next substitutions in every piece of text between matches foreach ($pieces as $k => $v) { if (strlen($v)) $pieces[$k] = str_replace_clean($search, $replace, $v); } } $subject = join($replace_text, $pieces); break; } } return $subject; } To test: echo str_replace_clean($search, $replace, $subject); // echoes "two three one" -- Xavier http://php.net/manual/en/function.str-replace.php