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

/
/
ig

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 = "[NMS]\\w+\\-\\w*BASE\\w*\\.AD\\.DTI"; final String string = "MAVM-WLBASE1a.ad.dti.\n" + "MAVM-WLBASE2a.ad.dti.\n" + "MAVM-WLBASE3a.ad.dti.\n" + "MAVM-WLBASE4a.ad.dti.\n" + "MAVM-WLBASE5a.ad.dti.\n" + "NJ-BASEQA2015.ad.dti.\n" + "NJVM-BASEQA2014.ad.dti.\n" + "NJVM-WLBASE6b.ad.dti.\n" + "NJVM-WLBASE7a.ad.dti.\n" + "NY2-BASEQA.ad.dti.\n" + "NY2-DW5BASEQA01.ad.dti.\n" + "SHVM-WLBASE1A.ad.dti.\n" + "NJ-ODEV2015.ad.dti.\n" + "NJ-ODEV2015b.ad.dti.\n" + "NJVM-ODEV2014.ad.dti.\n" + "NY2-ODEV2017.ad.dti.\n" + "SH-ODEV2017.ad.dti.\n" + "MOVM-WL12C.ad.dti.\n" + "NJ-PASWL12c01.ad.dti.\n" + "NJ-WL12cSVT01.ad.dti.\n" + "NJVM-WL12CUST1.ad.dti.\n" + "NJVM-wl12cust2.ad.dti.\n" + "njvm-wl12cust4.ad.dti.\n" + "njvm-wl12x64j7a.ad.dti.\n" + "NY2-WL12asp01.ad.dti.\n" + "NY2-WL12ASP02.ad.dti.\n" + "NY2-WL12ASP03.ad.dti.\n" + "NY2-WL12ASP04.ad.dti.\n" + "SH-AutoITWL12.ad.dti.\n" + "SH-PASWL12c02.ad.dti.\n" + "SHVM-WL12-RE.ad.dti.\n" + "SHVM-WL12CUST3.ad.dti.\n" + "ASP-WL1213INT01.asp.ad.dti.\n" + "ASP-WL12CEXT5.asp.ad.dti.\n" + "ASPVM-WL12c10.asp.ad.dti.\n" + "ASPVM-WL12c8.asp.ad.dti.\n" + "ASPVM-WL12c9.asp.ad.dti.\n" + "LT-MPROEKT.ad.dti.\n" + "LT-jpo01.ad.dti\n" + "LT-jpo01.adXdti"; final Pattern pattern = Pattern.compile(regex, Pattern.CASE_INSENSITIVE); 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