查找具有特殊字符的字符串的最后一个单词

Question

I am trying to add a span tag to the last word of a string. It works if the string has no special characters. I can't figure out the correct regex for it.

$string = "Onun Mesajı";
echo preg_replace("~\W\w+\s*\S?$~", ' <span>' . '\\0' . '</span>', $string);

Here is the Turkish character set : ÇŞĞÜÖİçşğüöı

Answer 1

You need to use /u modifier to allow processing Unicode characters in the pattern and input string.

preg_replace('~\w+\s*$~u', '<span>$0</span>', $string); 
                       ^

Full PHP demo :

$string = "Onun Mesajı";
echo preg_replace("~\w+\s*$~u", '<span>$0</span>', $string);

Also, the regex you need is just \\w+\\s*$ :

• \\w+ - 1 or more alphanumerics
• \\s* - 0 or more whitespace (trailing)
• $ - end of string

Since I removed the \\W from the regex, there is no need to "hardcode" the leading space in the replacement string (removed, too).

Answer 2

You should use the u modifier for regular expressions to set the engine into unicode mode:

<?php
$subject = "Onun äöüß Mesajı";
$pattern = '/\w+\s*?$/u';
echo preg_replace($pattern, '<span>\\0</span>', $subject);

The output is:

Onun äöüß <span>Mesajı</span>

Answer 3

This regex will do the trick for you, and is a lot shorter then the other solutions:

[ ](.*?$)

Here is an example of it:

$string = "Onun Mes*ÇŞĞÜÖİçşğüöıajı";
echo preg_replace('~[ ](.*?$)~', ' <span>' .'${1}'. '</span>', $string);

Will echo out:

Onun <span>Mes*ÇŞĞÜÖİçşğüöıajı</span>

The way this regex works is that we look for any characters without space in lazy mode [ ].*? .
then we add the $ identifier, so it matches from the end of the string instead.