How to replace all non-alphabetic characters with UTF-8 support in PHP

UPDATE: As for Unicode, RegExp will look like this [^\p{L}\s]+ (without replacing spaces)

It will replace all non-alpha characters with UTF8 support.

• \P{L}+ - matches any non-letter symbols
• \p{P}+ - removes punctuation only

Here are some reference docs that can be helpful:

• Tutorial on RegExp UTF8
• Unicode character properties

Use the Unicode character properties:

$str = preg_replace('/\P{L}+/u', '', $str);