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

/
/
gUs

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 = "<\\s*?script\\s*?([^>]*)\\s*?>\\s*?(.+)?\\s*?<\\s*?\\/script\\s*?>"; final String string = "< script type=\"text/javascript\" src=\"//vk.com/js/api/openapi.js?65\"> < /script >\n\n" + "<script type=\"text/javascript\" >\n" + " VK.init({apiId: 3251711, onlyWidgets: true});\n" + "</script>\n\n" + "<script type=\"text/javascript\" src=\"http://keddr.com/wp-content/themes/keddr3-1/js/lite-youtube.js\" ></script>\n\n" + "<script type=\"text/javascript\" src=\"http://keddr.com/wp-content/themes/keddr3-1/js/jquery.complexify.js\" > sfdbb </script>\n\n" + "<script type=\"text/javascript\" >\n" + " $(function () {\n" + " if (($(\"#pass1\").length 0)) {\n" + " $(\"#pass1\").complexify({}, function (valid, complexity) {\n" + " if (complexity < 1) {\n" + " $('#progress').css({'width': complexity + '%'}).removeClass('progressbarValidGood').addClass('progressbarInvalid');\n" + " $('.passAlert').hide();\n" + " } else if (complexity > 1 && complexity < 40) {\n" + " $('#progress').css({'width': complexity + '%'}).removeClass('progressbarValidGood').addClass('progressbarInvalid');\n" + " $('.passAlert.good').hide();\n" + " $('.passAlert.bad').fadeIn();\n" + " } else if (complexity > 40) {\n" + " $('#progress').css({'width': complexity + '%'}).removeClass('progressbarValidGood').addClass('progressbarValid');\n" + " $('.passAlert.good').hide();\n" + " $('.passAlert.strong').fadeIn();\n" + " }\n" + " $('#complexity').html(Math.round(complexity) + '%');\n" + " });\n" + " }\n" + " }); \n" + " \n" + "</script >"; final Pattern pattern = Pattern.compile(regex, Pattern.UNICODE_CHARACTER_CLASS | Pattern.DOTALL); 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