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

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "(?:\\d{1,3})\\s+(?:Platform Alarm\\(\\d+\\))\\s+\\d+\\s+(\\d+).+(\\d{4}-\\d{2}-\\d{2} \\d{2}:\\d{2}:\\d{2}).+nodeBId:(\\d+).+Office Name\\(Site\\)=([\\w_]+)"; final String string = "277 Platform Alarm(20420) 1337 198092557 User-defined dry contact alarm 8 Minor SubNetwork=75,MEID=5721,Equipment=1,Rack=1,SubRack=1,Slot=13 2021-06-21 04:27:39 U RNCId: 75; Dry contact ID: 6; Board serial number: 274808900275; U nodeBId:5721 Office ID(Site)=5721/Office Name(Site)=San_Telmo/Alarm Object Type=SDR/Alarm Object ID=5721/Alarm Object Name=San_Telmo/Board Type=SA 75-5721-1_1_13_1_198092557_6\n\n" + "12 Radio Controller(1701) 100001 41591 1615258887314 Processing Alarm 83886256 NodeB is out of service Critical SubNet(75)/ManagedElement(75)/Rack No.(1)/Shelf No.(1)/Board No.(8)/CPU No.(1) 2021-03-29 20:08:33 Alarm Object:NODEB; \\nNodeB ID:5433; \\nAlarm sub code:2; \\nIub Transport bearer type:IP V4 Bearer Type; \\nLink Number:1; \\nLink ID list:1126;\\nLogic Position:System No.:0,Module No.:7,Index:0; RNCSCB04 83886768 NCP link failure Office ID(Site)=5433/Office Name(Site)=Tariba/Alarm Object Type=NODEB/Alarm Object ID=5433/Alarm Object Name=Tariba/Board Type=CDR/APP Type=product:wcdma,wcdma/Object MOC=UIUBLINK/Object DN=SubNetwork=75,MEID=75,URncFunction=75,UIubLink=5433\n"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); while (matcher.find()) { System.out.println("Full match: " + matcher.group(0)); for (int i = 1; i <= matcher.groupCount(); i++) { System.out.println("Group " + i + ": " + matcher.group(i)); } } } }

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