(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.
patternThe 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.
stringThe string being checked.
optionsThe 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
// $matches[1] the match for the first subpattern
// enclosed in '(...)' and so on
return $matches[1].($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
<?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.