Can regular expressions work with different languages?

Short answer: yes.

More specifically it depends on your regex engine supporting unicode matches (as described here).

Such matches can complicate your regular expressions enormously, so I can recommend reading this unicode regex tutorial (also note that unicode implementations themselves can be quite a mess so you might also benefit from reading Joel Spolsky's article about the inner workings of character sets).

"[\p{L}]" This regular expression contains all characters that are letters, from all languages, upper and lower case. so letters like (a-z A-Z ä ß è 正 の文字を理解) are accepted but signs like (, . ? > :) or other similar ones are not.

• the brackets [] mean that this expression is a set.
• If you want unlimited number of letters from this set to be accepted, use an astrix * after the brackets, like this: "[\p{L}]*"
• it is always important to make sure you take care of white space in your regex. since your evaluation might fail because of white space. To solve this you can use: "[\p{L} ]*" (notice the white space inside brackets)
• If you want to include the numbers as well, "[\p{L|N} ]*" can help. p{N} matches any kind of numeric character in any script.