sentence: Many programming languages use or support regular expressions.
sentences_before: A 'regular expression' is a way to describe sets of characters using syntactic rules.
sentences_after: A regular expression is then used by a special program or part of a programming language. This program will either generate a parser that can be used to match expressions or it will match such expressions itself.
concept_name: programming language
headings: Regular expression
categories: Theoretical computer science