Allowed HTML 4.01 id values regex

Question

Can you help me to build a regex that matches a valid W3C HTML 4.01 id value?

According with W3C specs:

ID and NAME tokens must begin

Answer 1

You can use this regex

^[a-zA-Z][\w:.-]*$

^ depicts the start of string

[a-zA-Z] matches an uppercase or lowercase letter

* matches the preceding character 1 to many times

\w is similar to [a-zA-Z\d_]

$ is the end of string