Perform a regular expression search and replace with multibyte support using a callback (original) (raw)

mb_ereg_replace_callback

(PHP 5 >= 5.4.1, PHP 7)

mb_ereg_replace_callback — Perform a regular expression search and replace with multibyte support using a callback

Description

mb_ereg_replace_callback ( string $pattern , callable $callback , string $string [, string $option = "msr" ] ) : string

The behavior of this function is almost identical to mb_ereg_replace(), except for the fact that instead ofreplacement parameter, one should specify acallback.

Parameters

pattern

The regular expression pattern.

Multibyte characters may be used in pattern.

callback

A callback that will be called and passed an array of matched elements in the subject string. The callback should return the replacement string.

You'll often need the callback function for a mb_ereg_replace_callback() in just one place. In this case you can use ananonymous function to declare the callback within the call tomb_ereg_replace_callback(). By doing it this way you have all information for the call in one place and do not clutter the function namespace with a callback function's name not used anywhere else.

string

The string being checked.

option

The search option. See mb_regex_set_options() for explanation.

Return Values

The resultant string on success, or FALSE on error.

Notes

Note:

The internal encoding or the character encoding specified by mb_regex_encoding()will be used as the character encoding for this function.

Examples

Example #1 mb_ereg_replace_callback() example

<?php // this text was used in 2002 // we want to get this up to date for 2003 $text = "April fools day is 04/01/2002\n"; $text.= "Last christmas was 12/24/2001\n"; // the callback function function next_year($matches) { // as usual: $matches[0] is the complete match // $matches[1] the match for the first subpattern // enclosed in '(...)' and so on return <math xmlns="http://www.w3.org/1998/Math/MathML"><semantics><mrow><mi>m</mi><mi>a</mi><mi>t</mi><mi>c</mi><mi>h</mi><mi>e</mi><mi>s</mi><mo stretchy="false">[</mo><mn>1</mn><mo stretchy="false">]</mo><mi mathvariant="normal">.</mi><mo stretchy="false">(</mo></mrow><annotation encoding="application/x-tex">matches[1].(</annotation></semantics></math>matches[1].(matches[2]+1); } echo mb_ereg_replace_callback( "(\d{2}/\d{2}/)(\d{4})", "next_year", $text);?>

The above example will output:

April fools day is 04/01/2003 Last christmas was 12/24/2002

Example #2 mb_ereg_replace_callback() using anonymous function supported in PHP 5.3.0 or later

`<?php
// this text was used in 2002
// we want to get this up to date for 2003
$text = "April fools day is 04/01/2002\n";
$text.= "Last christmas was 12/24/2001\n";

echo

mb_ereg_replace_callback(
"(\d{2}/\d{2}/)(\d{4})",
function ($matches) {
return matches[1].(matches[1].(matches[1].(matches[2]+1);
},
$text);
?> `