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

/
/
gm

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "\\S.\\w+"; final String string = "3 \n" + " behnnam 12 157 282 55 308 159 \n" + "4 \n" + " qmohu 12 035 048 112 050 92 \n" + "5 \n" + " yufi71 4 637 190 66 488 366 \n" + "6 \n" + " Rohirrim_16 3 026 111 88 140 500 \n" + "7 \n" + " Nelliell 2 408 324 37 561 322 \n" + "8 \n" + " Knighteer 2 225 014 111 877 445 \n" + "9 \n" + " -suvari- 2 200 538 96 095 498 \n" + "10 \n" + " farukcakir 1 896 439 47 117 173 \n" + "11 \n" + " bobo342 1 767 789 133 470 479 \n" + "12 \n" + " Nawaf2u 1 701 184 11 020 171 \n" + "13 \n" + " korkuteke 1 646 584 18 821 376 \n" + "14 \n" + " aslkrslan 1 213 415 3 451 204 \n" + "15 \n" + " cinek31 1 157 463 7 912 230 \n" + "16 \n" + " 61pusat61 1 152 810 17 215 104 \n" + "17 \n" + " sladdin 1 031 630 19 556 312 \n" + "18 \n" + " devilsblade 908 424 37 133 375 \n" + "19 \n" + " krzychu4321 869 630 45 454 475 \n" + "20 \n" + " lacivertly1 868 405 30 795 457 \n" + "21 \n" + " orklar-tr 635 614 9 142 449 \n" + "22 \n" + " Doganbey1993 623 343 9 409 62 \n" + "23 \n" + " eagle_37800 592 185 25 424 389 \n" + "24 \n" + " cavidov 570 925 37 045 79 \n" + "25 \n" + " mbardakci 541 223 9 903 169 \n" + "26 \n" + " karasahin55tr 538 393 19 545 291 \n" + "27 \n" + " salvatordemon 517 475 2 248 127 \n" + "28 \n" + " secooooooo 401 102 12 641 236 \n" + "29 \n" + " synfrkn 360 119 14 243 375 \n" + "30 \n" + " gingso 218 393 5 373 355 \n"; final String subst = ""; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); // The substituted value will be contained in the result variable final String result = matcher.replaceAll(subst); System.out.println("Substitution result: " + 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 Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html