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
No Match

/
/
g

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"( \d{1,2})5(\d{2} )").unwrap(); let string = "part1.htm\">MiniTOC</a><a class=\"toc1\" part2.htm\">2/5/18, 4549 PM part3.htm\">2/7/18, 4516 PM part4.htm\">2/15/18, 2557 PM part5.htm\">2/20/18, 2507 PM part6.htm\">2/21/18, 3502 PM part7.htm\">2/21/18, 5506 PM part8.htm\">2/22/18, 10503 AM part9.htm\">2/22/18, 1543 PM part10.htm\">2/27/18, 3514 PM part11.htm\">2/28/18, 2533 PM part12.htm\">3/1/18, 1515 PM part13.htm\">3/1/18, 2527 PM part14.htm\">3/1/18, 6547 PM part15.htm\">3/1/18, 8557 PM part16.htm\">3/4/18, 11540 AM part17.htm\">3/5/18, 4546 PM part18.htm\">3/6/18, 12548 PM part19.htm\">3/6/18, 2518 PM part20.htm\">3/7/18, 12535 PM part21.htm\">3/8/18, 8500 AM part22.htm\">3/8/18, 10521 AM part23.htm\">3/8/18, 12559 PM part24.htm\">3/9/18, 10540 AM part25.htm\">3/9/18, 1501 PM part26.htm\">3/9/18, 6514 PM part27.htm\">3/12/18, 8514 PM part28.htm\">3/14/18, 12520 PM part29.htm\">3/14/18, 2537 PM part30.htm\">3/15/18, 2514 PM part31.htm\">3/15/18, 3549 PM part32.htm\">3/21/18, 11506 AM part33.htm\">3/22/18, 2518 PM part34.htm\">3/22/18, 3523 PM part35.htm\">3/22/18, 4554 PM part36.htm\">3/26/18, 3543 PM part37.htm\">4/2/18, 1555 PM part38.htm\">4/2/18, 4532 PM part39.htm\">4/5/18, 1557 PM part40.htm\">4/6/18, 4536 PM part41.htm\">4/6/18, 5540 PM part42.htm\">4/6/18, 7501 PM part43.htm\">4/7/18, 5524 AM part44.htm\">4/16/18, 12525 PM part45.htm\">4/17/18, 4502 PM part46.htm\">4/23/18, 7520 PM part47.htm\">4/25/18, 3527 PM part48.htm\">4/25/18, 5513 PM part49.htm\">4/26/18, 2534 PM part50.htm\">4/26/18, 6513 PM part51.htm\">5/1/18, 3523 PM part52.htm\">5/3/18, 3540 PM part53.htm\">5/4/18, 12539 PM part54.htm\">5/8/18, 12539 PM part55.htm\">5/8/18, 2549 PM part56.htm\">5/9/18, 12506 PM part57.htm\">5/15/18, 3525 PM part58.htm\">5/23/18, 6545 PM part59.htm\">5/24/18, 2559 PM part60.htm\">5/24/18, 5523 PM part61.htm\">5/26/18, 3509 PM part62.htm\">5/27/18, 11519 AM part63.htm\">5/30/18, 4554 PM part64.htm\">5/26/18, 1507 PM part65.htm\">5/31/18, 2558 PM part66.htm\">6/7/18, 2546 PM part67.htm\">6/11/18, 7531 PM part68.htm\">6/12/18, 10547 AM part69.htm\">6/12/18, 3529 PM part70.htm\">6/13/18, 7536 PM part71.htm\">6/14/18, 3527 PM part72.htm\">6/19/18, 8507 AM part73.htm\">6/19/18, 3528 PM part74.htm\">6/19/18, 5519 PM part75.htm\">6/20/18, 10507 AM part76.htm\">6/21/18, 10545 AM part77.htm\">6/21/18, 12544 PM part78.htm\">6/21/18, 3534 PM part79.htm\">6/23/18, 11506 AM part80.htm\">6/23/18, 3505 PM part81.htm\">6/23/18, 6500 PM part82.htm\">6/24/18, 10535 AM part83.htm\">6/24/18, 12556 PM part84.htm\">6/25/18, 7517 PM part85.htm\">6/26/18, 3517 PM part86.htm\">6/26/18, 4559 PM part87.htm\">6/27/18, 9551 AM </a><a class=\"toc1\" part88.htm\">6/27/18, 11532 AM part89.htm\">6/28/18, 4515 PM </a><a class=\"toc1\" part90.htm\">7/2/18, 6529 PM part91.htm\">7/3/18, 3554 PM part92.htm\">7/3/18, 5545 PM part93.htm\">7/3/18, 7556 PM part94.htm\">7/3/18, 9503 PM part95.htm\">7/7/18, 5531 PM part96.htm\">7/9/18, 4553 PM part97.htm\">7/10/18, 8554 AM part98.htm\">7/10/18, 5516 PM part99.htm\">7/11/18, 11531 AM part100.htm\">7/11/18, 3550 PM part101.htm\">7/12/18, 4549 PM part102.htm\">7/15/18, 3524 PM part103.htm\">7/16/18, 10525 AM part104.htm\">7/16/18, 11534 AM part105.htm\">7/16/18, 6544 PM part106.htm\">7/18/18, 11505 AM part107.htm\">7/19/18, 1537 PM part108.htm\">7/19/18, 3532 PM part109.htm\">7/24/18, 10500 AM part110.htm\">7/24/18, 2514 PM part111.htm\">7/24/18, 3555 PM part112.htm\">7/24/18, 7506 PM part113.htm\">8/9/18, 12537 PM part114.htm\">8/13/18, 3531 PM part115.htm\">8/13/18, 5551 PM part116.htm\">8/14/18, 12509 PM part117.htm\">8/14/18, 1532 PM part118.htm\">8/14/18, 3539 PM part119.htm\">8/16/18, 4548 PM part120.htm\">8/16/18, 4548 PM part121.htm\">8/21/18, 6509 PM part122.htm\">8/23/18, 11557 AM part123.htm\">8/28/18, 4537 PM part124.htm\">8/30/18, 7528 PM part125.htm\">8/30/18, 10500 PM part126.htm\">9/4/18, 2538 PM part127.htm\">9/4/18, 5515 PM part128.htm\">9/5/18, 3538 PM part129.htm\">9/7/18, 5519 PM part130.htm\">9/10/18, 3518 PM part131.htm\">9/13/18, 8541 AM part132.htm\">9/13/18, 11512 AM part133.htm\">9/13/18, 12551 PM part134.htm\">9/17/18, 6502 PM part135.htm\">9/18/18, 3555 PM part136.htm\">9/19/18, 9506 PM part137.htm\">9/19/18, 11504 PM part138.htm\">9/20/18, 12531 PM part139.htm\">9/24/18, 4502 PM part140.htm\">9/24/18, 6518 PM part141.htm\">9/25/18, 9550 AM part142.htm\">9/25/18, 5512 PM part143.htm\">9/26/18, 12549 PM part144.htm\">9/26/18, 6533 PM part145.htm\">9/28/18, 9543 AM part146.htm\">10/1/18, 7558 AM part147.htm\">10/1/18, 3538 PM part148.htm\">10/3/18, 10551 AM part149.htm\">10/3/18, 3521 PM part150.htm\">10/3/18, 4528 PM part151.htm\">10/3/18, 5529 PM part152.htm\">10/8/18, 11521 AM part153.htm\">10/8/18, 2526 PM part154.htm\">10/8/18, 4538 PM part155.htm\">10/9/18, 1504 PM part156.htm\">10/9/18, 4529 PM part157.htm\">10/9/18, 6552 PM part158.htm\">10/10/18, 6509 PM part159.htm\">10/11/18, 1544 PM part160.htm\">10/11/18, 3527 PM part161.htm\">10/11/18, 5552 PM part162.htm\">10/11/18, 8500 PM part163.htm\">10/16/18, 2515 PM part164.htm\">10/16/18, 4501 PM part165.htm\">10/18/18, 10541 AM part166.htm\">10/18/18, 1505 PM part167.htm\">10/18/18, 4524 PM part168.htm\">10/18/18, 7537 PM part169.htm\">10/19/18, 11532 AM part170.htm\">10/22/18, 9539 AM part171.htm\">10/22/18, 10543 AM part172.htm\">10/22/18, 12514 PM part173.htm\">10/22/18, 2523 PM part174.htm\">10/24/18, 10506 AM part175.htm\">10/24/18, 12535 PM part176.htm\">10/24/18, 5558 PM part177.htm\">11/1/18, 3525 PM part178.htm\">11/1/18, 3525 PM part179.htm\">11/5/18, 11509 AM part180.htm\">11/5/18, 1544 PM part181.htm\">11/8/18, 6521 PM part182.htm\">11/9/18, 11538 AM part183.htm\">11/10/18, 11525 AM part184.htm\">11/10/18, 2531 PM part185.htm\">11/14/18, 10530 AM part186.htm\">11/14/18, 2505 PM part187.htm\">11/14/18, 4521 PM part188.htm\">11/14/18, 5527 PM part189.htm\">11/15/18, 11541 AM part190.htm\">11/15/18, 12558 PM part191.htm\">11/18/18, 8559 PM part192.htm\">11/19/18, 11502 AM part193.htm\">11/19/18, 12512 PM part194.htm\">11/26/18, 12537 PM part195.htm\"> 11/27/18, 3535 PM part196.htm\">11/28/18, 9535 AM part197.htm\">11/28/18, 12551 PM part198.htm\">11/29/18, 11541 AM part199.htm\">12/3/18, 11512 AM part200.htm\">12/3/18, 4501 PM part201.htm\">12/4/18, 12510 PM part202.htm\">12/4/18, 2504 PM part203.htm\">12/4/18, 3559 PM part204.htm\">12/7/18, 11548 AM part205.htm\">12/7/18, 1542 PM part206.htm\">12/10/18, 12521 PM part207.htm\">12/11/18, 12518 PM part208.htm\">12/14/18, 9517 AM part209.htm\">12/14/18, 11554 AM part210.htm\">12/14/18, 1547 PM part211.htm\">12/14/18, 3530 PM part212.htm\">12/14/18, 9531 PM part213.htm\">12/16/18, 6506 PM part214.htm\">12/17/18, 11556 AM part215.htm\">12/19/18, 4500 PM part216.htm\">12/20/18, 2558 PM part217.htm\">12/20/18, 7516 PM part218.htm\">12/21/18, 4516 PM part219.htm\">12/21/18, 7510 PM part220.htm\">12/25/18, 10518 PM part221.htm\">1/1/19, 10540 AM part222.htm\">1/1/19, 3521 PM part223.htm\">1/3/19, 6501 PM part224.htm\">1/4/19, 11540 AM part225.htm\">1/4/19, 2501 PM part226.htm\">1/4/19, 3555 PM part227.htm\">1/6/19, 2519 PM part228.htm\">1/7/19, 9531 AM part229.htm\">1/7/19, 11527 AM part230.htm\">1/7/19, 9532 PM part231.htm\">1/8/19, 10534 PM part232.htm\">1/9/19, 1512 PM part233.htm\">1/10/19, 9551 AM part234.htm\">1/10/19, 5537 PM part235.htm\">1/11/19, 12526 PM part236.htm\">1/14/19, 12522 PM part237.htm\">1/13/19, 6555 PM part238.htm\">1/11/19, 1557 PM part239.htm\">1/17/19, 9539 AM part240.htm\">1/17/19, 3513 PM part241.htm\">1/18/19, 1505 PM part242.htm\">1/18/19, 2549 PM part243.htm\">1/22/19, 9557 AM part244.htm\">1/22/19, 3530 PM part245.htm\">1/24/19, 12532 PM part246.htm\">1/24/19, 2554 PM part247.htm\">1/25/19, 2554 PM part248.htm\">1/29/19, 9552 AM part249.htm\">1/30/19, 8528 AM part250.htm\">1/30/19, 11550 AM part251.htm\">2/1/19, 9506 AM part252.htm\">2/1/19, 11529 AM part253.htm\">2/1/19, 12557 PM part254.htm\">2/1/19, 4522 PM part255.htm\">2/2/19, 8519 AM part256.htm\">2/5/19, 1500 PM part257.htm\">2/5/19, 3537 PM part258.htm\">2/7/19, 2534 PM part259.htm\">2/8/19, 3526 PM part260.htm\">2/8/19, 5510 PM part261.htm\">2/11/19, 4538 PM part262.htm\">2/12/19, 10555 AM part263.htm\">2/13/19, 2514 PM part264.htm\">2/13/19, 4533 PM part265.htm\">2/13/19, 8537 PM part266.htm\">2/14/19, 8544 AM part267.htm\">2/14/19, 10516 AM part268.htm\">2/14/19, 11543 AM part269.htm\">2/16/19, 2501 PM part270.htm\">2/16/19, 3541 PM part271.htm\">2/19/19, 7501 PM part272.htm\">2/20/19, 10526 AM part273.htm\">2/20/19, 12501 PM part274.htm\">2/20/19, 4534 PM part275.htm\">2/24/19, 10550 AM part276.htm\">2/24/19, 12506 PM part277.htm\">2/24/19, 12506 PM part278.htm\">2/25/19, 1541 PM part279.htm\">2/25/19, 4554 PM part280.htm\">2/28/19, 2522 PM part281.htm\">3/6/19, 12522 PM part282.htm\">3/7/19, 12522 PM part283.htm\">3/7/19, 4517 PM part284.htm\">3/8/19, 2534 PM part285.htm\">3/12/19, 7514 PM part286.htm\">3/13/19, 11546 AM part287.htm\">3/13/19, 12552 PM part288.htm\">3/14/19, 2502 PM part289.htm\">3/15/19, 12545 PM part290.htm\">3/15/19, 4553 PM part291.htm\">3/18/19, 10522 AM part292.htm\">3/18/19, 11544 AM part293.htm\">3/18/19, 2536 PM part294.htm\">3/18/19, 4513 PM part295.htm\">3/19/19, 10506 AM part296.htm\">3/19/19, 1543 PM part297.htm\">3/20/19, 10530 AM part298.htm\">3/24/19, 11516 AM part299.htm\">3/24/19, 1533 PM part300.htm\">3/26/19, 8530 AM part301.htm\">3/28/19, 9507 PM part302.htm\">3/29/19, 8523 AM part303.htm\">4/2/19, 10504 AM part304.htm\">4/2/19, 11534 AM part305.htm\">4/2/19, 1508 PM "; let substitution = "\\1:\\2"; // 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/