Regular expression tester with syntax highlighting, explanation, cheat sheet for PHP/PCRE, Python, GO, JavaScript, Java, C#/.NET, Rust.

Apr 12, 2024 · A regular expression (sometimes called a rational expression) is a sequence of characters that define a search pattern, mainly for use in pattern matching with strings, or string matching, i.e. “find and replace” like operations.

Oct 28, 2024 · This page provides an overall cheat sheet of all the capabilities of RegExp syntax by aggregating the content of the articles in the RegExp guide. If you need more information on a specific topic, please follow the link on the corresponding heading …

Jan 24, 2025 · Uses a regular expression or a fixed string to break a string into an array of substrings. When you want to know whether a pattern is found in a string, use the test() or search() methods; for more information (but slower execution) use the exec() or match() methods.

A regular expression (shortened as regex or regexp), [1] sometimes referred to as rational expression, [2] [3] is a sequence of characters that specifies a match pattern in text. Usually such patterns are used by string-searching algorithms for "find" or "find and replace" operations on strings, or for input validation.

Regular expressions or commonly called as Regex or Regexp is technically a string (a combination of alphabets, numbers and special characters) of text which helps in extracting information from text by matching, searching and sorting.

RegExr is an online tool to learn, build, & test Regular Expressions (RegEx / RegExp). Supports JavaScript & PHP/PCRE RegEx. Results update in real-time as you type. Roll over a match or expression for details. Validate patterns with suites of Tests. Save & share expressions with others. Use Tools to explore your results.

Feb 15, 2011 · What is the regex for simply checking if a string contains a certain word (e.g. 'Test')? I've done some googling but can't get a straight example of such a regex. This is for a build script but has no bearing to any particular programming language.

Jan 5, 2025 · Regular Expression Quick Reference Cheat Sheet. A quick start regex cheat sheet reference guide for regular expressions, including regex syntax, symbols, ranges, grouping, assertions, Unicode handling, and some practical examples.

A Regular Expression (or Regex) is a pattern (or filter) that describes a set of strings that matches the pattern. In other words, a regex accepts a certain set of strings and rejects the rest. A regex consists of a sequence of characters, metacharacters (such as ., \d, \D, \s, \S, \w, \W) and operators (such as +, *, ?, |, ^). They are ...