Question

I have a set of characters like

., !, ?, ;, (space)

and a string, which may or may not be UTF 8 (any language).

Is there a easy way to find out if the string has one of the character set above?

For example:

这是一个在中国的字符串。

which translates to

This is a string in chinese.

The dot character looks different in the first string. Is that a totally different character, or the dot correspondent in utf 8?

Or maybe there’s a list somewhere with Unicode punctuation character codes?

Answer 1

In Unicode there are character properties^{PHP Docs}, for example Symbols, Letters and the like. You can search for any string of a specific class with preg_match^Docs and the u modifier.

echo preg_match('/pP$/u', $str);

However, your string needs to be UTF-8 to do that.

You can test this on your own, I created a little script that tests for all properties via preg_match:

Looking for properties of last character in "Test.":
Found Punctuation (P).
Found Other punctuation (Po).

Looking for properties of last character in "这是一个在中国的字符串。":
Found Punctuation (P).
Found Other punctuation (Po).

Related: PHP – Fast way to strip all characters not displayable in browser from utf8 string.