Regular Expressions 101

Save & Share

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

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
No Match

r"
"
gm

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"(?m)(^S[A-Z]*\ [0-9\.]*$)").unwrap(); let string = "Aokia How doers getmore done. 9615 DIAMOND CENTER DRIVE MENTOR, OH 44060 (440)357-0428 3815 00061 42905 05/01/22 01:57PM SALE SELF CHECKOUT 037155808113 DRAIN CRT <A> 15.88 CHROME FINISH PLASTIC TUB STOPPER SUBTOTAL 15.88 SALES TAX 1.15 TOTAL $17.03 XXXXXXXXXXXX4651 DEBIT USD$17.03 AUTH CODE 001059 Chip Read Verified By PIN AID A0000000042203 US Debit 3815 05/01/22 01:57 PM 3815 61 42905 05/01/2022 9250 RETURN POLICY DEFINITIONS POLICY ID DAYS POLICY EXPIRES ON A 1 90 07/30/2022 **** DID WE NAIL IT? Take a short survey for a chance TO WIN A$5,000 HOME DEPOT GIFT CARD Opine en español www.homedepot.com/survey User ID: H88 89914 86160 PASSWORD: 22251 86099 Entries must be completed within 14 days of purchase. Entrants must be 18 or older to enter. See complete rules on website. No purchase necessary."; // result will be an iterator over tuples containing the start and end indices for each match in the string let result = regex.captures_iter(string); for mat in result { println!("{:?}", mat); } }

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/