Regular Expressions 101

Save & Manage Regex

  • Current Version: 1
  • 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

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 = ".*(idMatches):\\n(?s)(.+?)(Close: )(?s)(.+?)$"; final String string = "<ENG6_6701>\n" + "idMatches:\n\n" + "Close: ENG6_6701\n\n" + "<ENG6_7211>\n" + "idMatches:\n\n" + "Close: ENG6_7211\n\n" + "<ENG6_4474>\n" + "idMatches:\n" + "04\\B\\_3\\IFM_2017.30_App.CrashMonitor.CrashMonitor:11098: <testcase name=\"SysRS_3104_row 1\" type=\"1\" id=\"11177\" foreign_id=\"0\" testdata_id=\"1073741963\" state_mask=\"0x1100\" testcase_number=\"8\" child_count=\"1\" description=\"ENG6_4474\" specification=\"\" comment=\"\" uuid=\"c0a39548-d902-4a76-b986-3f0c49e7f8b1\" testitem_state_mask=\"0x80\" usercode_state_mask=\"0x00\" last_modified=\"1587729309934\" last_synchronized=\"0\">\n" + "04\\B\\_3\\IFM_2017.30_App.CrashMonitor.CrashMonitor.tmb:11098: <testcase name=\"SysRS_3104_row 1\" type=\"1\" id=\"11177\" foreign_id=\"0\" testdata_id=\"1073741963\" state_mask=\"0x1100\" testcase_number=\"8\" child_count=\"1\" description=\"ENG6_4474\" specification=\"\" comment=\"\" uuid=\"c0a39548-d902-4a76-b986-3f0c49e7f8b1\" testitem_state_mask=\"0x80\" usercode_state_mask=\"0x00\" last_modified=\"1587729309934\" last_synchronized=\"0\">\n" + "04\\G\\0\\IFM_2017.30_App.CrashMonitor.CrashMonitor.CrashMonitor_Main.script:645: ENG6_4474\n" + "06\\05\\EE\\IFM_2017.30_App.CrashMonitor.CrashMonitor:10507: <testcase name=\"SysRS_3104_row 1\" type=\"1\" id=\"4573\" foreign_id=\"0\" testdata_id=\"1073741963\" state_mask=\"0x5B00\" testcase_number=\"37\" child_count=\"1\" description=\"ENG6_4474\" specification=\"\" comment=\"\" uuid=\"c0a39548-d902-4a76-b986-3f0c49e7f8b1\" testitem_state_mask=\"0x80\" usercode_state_mask=\"0x00\" last_modified=\"1587560383700\" last_synchronized=\"0\">\n" + "06\\10\\00\\Crasmonitor\\IFM_2017.30_App.CrashMonitor.CrashMonitor.CrashMonitor_Main.script:220: ENG6_4474\n\n" + "Close: ENG6_4474\n\n" + "<ENG6_4475>\n\n" + "NOTE: it was needed to change the first \\n for a \\r"; final String subst = "\\t<\\1>\\n\\t\\t\\2\\t</\\1>\\n</\\4>\\n"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); 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