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

Jan 8, 2026 · Regular expression syntax cheat sheet 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.

In Python-style regex, \d matches any individual digit. If you're seeing something that doesn't seem to do that, please provide the full regex you're using, as opposed to just describing that one particular symbol.

Regular expression tester with syntax highlighting, PHP / PCRE & JS Support, contextual help, cheat sheet, reference, and searchable community patterns.

Mar 2, 2023 · This article showed you what the \d RegEx metacharacter is and how to use it. We looked at some examples and also compared it with the digit character set, [0-9], so you can know how they …

Regular Expression Search and Replace can be done with different methods. These are the most common: /\D/ is an ECMAScript1 (JavaScript 1997) feature. It is supported in all browsers:

If you are a complete beginner, you should get a firm grasp of basic regex syntax just by reading the examples in the tables. I tried to introduce features in a logical order and to keep out oddities that I've …

Dec 22, 2025 · A regular expression (regex) is a sequence of characters that defines a search pattern. It is mainly used for pattern matching in strings, such as finding, replacing, or validating text. Regex is …

Jun 18, 2022 · In this quick reference, learn to use regular expression patterns to match input text. A pattern has one or more character literals, operators, or constructs.

Jan 9, 2026 · In a regular expression, shorthand character classes match a single character from a predefined set of characters.