(PHP 5 >= 5.4.1, PHP 7, PHP 8)
mb_ereg_replace_callback — Perform a regular expression search and replace with multibyte support using a callback
$pattern
,$callback
,$string
,$options
= null
Scans string
for matches to pattern
, then replaces the matched text with the output of callback
function.
The behavior of this function is almost identical to mb_ereg_replace(), except for the fact that instead of replacement
parameter, one should specify a callback
.
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 string
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 an anonymous function to declare the callback within the call to mb_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.
options
The search option. See mb_regex_set_options() for explanation.
The resultant string on success, or false
on error. If string
is not valid for the current encoding, null
is returned.
Version | Description |
---|---|
8.0.0 | options is nullable now. |
7.1.0 | The function checks whether string is valid for the current encoding. |
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
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
<?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[2]+1);
},
$text);
?>
Note:
The internal encoding or the character encoding specified by mb_regex_encoding() will be used as the character encoding for this function.