Regular Expressions 101

Save & Manage Regex

  • Current Version: 2
  • Save & Share
  • Community Library

Flavor

  • PCRE2 (PHP)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java
  • .NET 7.0 (C#)
  • Rust
  • PCRE (Legacy)
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests
Sponsors
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
Processing...

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 = "<[^>]*>"; final String string = "</style></head><body dir=\"ltr\" style=\"max-width:21cm;margin-top:1cm; margin-bottom:1cm; margin-left:1cm; margin-right:1cm; \">\n" + " <p class=\"P11\">PRE-REGISTRATION</p>\n" + " <p class=\"P11\">FIL_RI_CHOP</p>\n" + " <p class=\"P1\"><span class=\"T3\">We confirm the completion of the pre-registration CRF for the patient <span class=\"T1\">1</span> enrolled in the study <span class=\"T1\">FIL_RI_CHOP</span>.</span><a id=\"_GoBack\"/><span class=\"T1\"></span></p>\n" + " \n" + " <p class=\"P1\">\n" + " <span class=\"T3\">Date: </span><span class=\"T1\">2018-08-03<br/></span>\n" + " <span class=\"T3\">Patient's Code: </span><span class=\"T1\">1<br/></span>\n" + " <span class=\"T3\">Center: </span><span class=\"T1\">17_Terni_S.Maria<br/></span>\n" + " <span class=\"T3\">User: </span><span class=\"T1\">site_admin<br/></span></p><p class=\"P1\">\n" + " \n" + " <span class=\"T3\">Uffici Studi FIL</span></p><p class=\"P1\">\n" + " <span class=\"T3\">Fondazione Italiana Linfomi ONLUS</span></p>"; final Pattern pattern = Pattern.compile(regex); final Matcher matcher = pattern.matcher(string); if (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