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"
"
gmu

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 = "([0-9]{1,2}:[0-9]{2}) (AM|PM)(\\n)(.*)\\n"; final String string = "5:47 PM\n" + "[EASY] Panzer Pebble joined the server\n" + "5:47 PM\n" + "Trigger executed raw command message \"76561199679367168\" Welcome to EASY Company | Level 50+! If you have any issues, please report it by typing !admin (reason) in chat. Come check us out at discord.gg/easycompany. You MUST be level 50 or higher to play on this server and level 75 or higher to play commander.\n" + "5:47 PM\n" + "Player [EASY] Panzer Pebble switched from None to Allies\n" + "5:47 PM\n" + "MESSAGE: player [[EASY] Panzer Pebble(76561199679367168)], content [We are trying to populate the server which means special rules apply.\n" + "5:56 PM\n" + "MESSAGE: player [[EASY] Panzer Pebble(76561199679367168)], content [Vote for the nextmap:\n" + "5:59 PM\n" + "MESSAGE: player [[EASY] Panzer Pebble(76561199679367168)], content [We are trying to populate the server which means special rules apply.\n" + "5:59 PM\n" + "MESSAGE: player [[EASY] Panzer Pebble(76561199679367168)], content [This server is under level thresholds control.\n" + "6:18 PM\n" + "Player [EASY] Panzer Pebble switched from None to Axis\n" + "7:28 PM\n" + "MESSAGE: player [[EASY] Panzer Pebble(76561199679367168)], content [Vote for the nextmap:\n" + "7:48 PM\n" + "MASTER CHIEF (Axis) killed [EASY] Panzer Pebble (Allies) with GEWEHR 43\n" + "7:49 PM\n" + "Yustitsiya (Axis) killed [EASY] Panzer Pebble (Allies) with MP40\n" + "9:00 PM\n" + "MESSAGE: player [[EASY] Panzer Pebble(76561199679367168)], content [Vote for the nextmap:"; final String subst = "\\g<1>\\g<2> \\g<4>\\n"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE | Pattern.UNICODE_CASE); 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