Regular Expressions 101

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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

Substitution
Processing...

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"(?i)by([^(b(?>y))])+").unwrap(); let string = "zzzzzzzzzzzzzzzzzzeererezzz By LITE-ON!Model: PA-1121-12H, PA-1121-12R!Series: PPP017L!HP Part No.: 316688-001, 394900-001, 393946-001!!By HIPRO!Model: HP-OW121F13!Series: PPP017H!HP Part No.: 316688-002!!By Fordgood!Model: 0309A18120!Series: PPP017S!HP Part No.: 316688-003 !Replace with HP Spare No.: 317188-001!Compatible HP Spare No.: 350775-001!!Input: 110-240V~ 2.5A, 50-60Hz!Output: 18.5V 6.5A 120W!Connecter size: Int. Diameter: 2.50mm Ext. Diameter: 5.50mm Length : 14.00mm!!Dimension: 168 x 62 x 37 mm!!*For use with Presario 3000xx notebook series.!!**Please take note, 3 wire AC power cord not included.!!/by([^(b(?>y))])+/gi"; let substitution = ""; // result will be a String with the substituted value let result = regex.replace_all(string, substitution); println!("{}", result); }

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/