c# Regular Expression

Regular Expression

Regex regularExpression = new Regex("^[a-zA-Z0-9_]*$");


//contains only upper and lowercase letters, numbers, and underscores.

* ^ : start of string

[ : beginning of character group

a-z : any lowercase letter

A-Z : any uppercase letter

0-9 : any digit

_ : underscore

] : end of character group

* : zero or more of the given characters

$ : end of string