JavaScript String Regular Expressions – Part 5 Introduction This is part 5 of my series JavaScript String Regular Expressions. Matching is case sensitive. You may not know if what you are looking for is in lower case or upper case or has mixed cases. It is possible for you to make a case insensitive match. You need what is called a flag for this. There are a good number of flags and each has its own purpose. We shall learn some of them in this part of the series. In this part of the series, we... Sign in to see full entry.