Regular Expression (Regex) Tutorial, Tools, Tester, Syntax

What is Regular Expression

In simple words it is a pattern of symbol and characters. Regular expression is used to search,replace or modify the words/strings. It is the most important part of your daily programming usage whether rewriting url using .htaccess, form validation, validating user input etc.

Regular expression is a sequence of characters and each characters has it’s special meaning. Let’s look at some basic characters and it’s meaning.