Regex to match only letters

Question

How can I write a regex that matches only letters?

Answer 1

Use a character set: [a-zA-Z] matches one letter from A–Z in lowercase and uppercase. [a-zA-Z]+ matches one or more letters and ^[a-zA-Z]+$ matches only strings that consist of one or more letters only (^ and $ mark the begin and end of a string respectively).

If you want to match other letters than A–Z, you can either add them to the character set: [a-zA-Z??ü???ü]. Or you use predefined character classes like the Unicode character property class p{L} that describes the Unicode characters that are letters.