What Is Regex ?

Regex or Regular Expression is a sequence of characters that are used to match a certain pattern in text. It could also be combinations of special character operators, which are symbols that control the search, that we can use for advanced find and/or replace searches.

The regex is applied on the text from left to right. Once a source character has been used in a match, it cannot be reused. For example, the regex aba will match ababababa only 2 times (aba_aba__).