JavaScript String Regular Expressions – Part 2 Introduction This is the second part of my series, JavaScript String Regular Expressions. In this part of the series, we start analyzing patterns in JavaScript Regular Expressions. Character Classes The Square Brackets A character class allows a set of possible characters, where one of them would match at a particular point, a character, in the subject string. Character classes are denoted by brackets [...], with the set (class) of characters to be... Sign in to see full entry.