Regular Expressions 101

Save & Manage Regex

  • Current Version: 1
  • Save & Share
  • Community Library

Flavor

  • PCRE2 (PHP)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java
  • .NET 7.0 (C#)
  • Rust
  • PCRE (Legacy)
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests
Sponsors
There are currently no sponsors. Become a sponsor today!
An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
Processing...

Test String

Code Generator

Language

Generated Code

// include the latest version of the regex crate in your Cargo.toml extern crate regex; use regex::Regex; fn main() { let regex = Regex::new(r"dXNpbmcgU3lzdGV.GtLklPOw0KdXNpbmcgU3lzdGVtOw0KDQpjbGFzcyBQcm9 ncmFtDQp7,eDQogICAgc3RhdGljIHZvaWQgTWFpbigpDQogICAgew0KICAgIC AgICBzdHJpbmcgbGluZSA9ICIwNTIgMDU1.hIDA1NCAwNTMgMDU0IDA1NiAwN TQgMDUzIDA1MCAwNDggMD,eU1IDA5NyAwNTUgMDUzIDA1MCAwNDggMDUyIDEw MSAwNT,zAgMDQ4IDA1MCAxMDEgMDUxIDA1MCAwNTEgMDUwIDA1MSAwNTEgMDU wIDA0OCAwNTIgMDUzIDA1MCAwNDggMDUwIDEwMSAwNT.uEgMDUyIDA1MSAwNT AgMDUxI,NDA1MyI7DQogICAgICAgIHN0cmluZ1tdIHNwbCA9IGxpbmUuU3Bsa XQobmV3IGNoYXJbXXsnICd9KTsNCiAgICAgI.2CAgZm9yZWFjaChzdHJpbmcg cyBpbi,1BzcGwpDQogICAgICAgIHsNCiAgICAgICAgICAgIGludCBkID0gU3l zdGVtLkNvbnZlcnQuVG9JbnQzMih.6zKTsNCiAgICAgICAgICAgIGNoYXIgYy A9IFN5c.E3RlbS5Db252ZXJ0LlRvQ2hhcihkKTsNCiAgICAgICAgICAgIENvb nNvbGUuV3JpdGUoYyk7DQogICAgICAgIH0gICAgDQogICA.4gfQ0KCS8vIGJp dC5s,1eS8xb2Z6d.63J2DQp9").unwrap(); let string = ""; // result will be a tuple containing the start and end indices for the first match in the string let result = regex.captures(string); let (start, end) = match result { Some((s, e)) => (s, e), None => { // ... } }; println!("{}", &string[start, end]); }

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Rust, please visit: https://docs.rs/regex/latest/regex/