Regular Expressions 101

Save & Share

  • Regex Version: ver. 2
  • Update Regex
    ctrl+⇧+s
  • Save new Regex
    ctrl+s
  • Add to Community Library

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

/
/
g

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 = "<li>(Pg_.*)<\\/li>"; final String string = "<ul>\n" + " <li><a href=\"#symbols\">Symbol report</a></li>\n" + "<ul>\n" + " <li><a href=\"#symbolsConsistency\">Consistency</a></li>\n" + " <li><a href=\"#symbolCharacteristics\">Symbol characteristics</a></li>\n" + " <li><a href=\"#basicSymbols\">Display of basic symbols</a></li>\n\n\n" + " <ul>\n" + " <li>Pg_1_qds_Bin_Indicator_2</li>\n" + " <ul>\n" + " <li>[QDSConsistency.report.field.logicIndicator.descriptionalignment] = (Right)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.descriptiontextcolor] = (Color {0, 0, 0, 255})</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.isdescriptiondisplayed] = (true)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.descriptionfontfamily] = (Arial)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.descriptionfontsize] = (11 pt)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.descriptionfontstyle] = (Normal)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.descriptionfontposition] = (LEFT)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.descriptiontext] = (v1)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.backgroundcolor] = (Color {238, 238, 238, 255})</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.digitnumber] = (8)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.widgetfont] = (FONT1)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.shortname] = (Pg_1_qds_Bin_Indicator_2)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.precision] = (2)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.widgetuserfontfamily] = (Arial)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.widgetuserfontsize] = (11 pt)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.widgetuserfontstyle] = (NORMAL)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.dynamicbackgroundcolor] = (Color {238, 238, 238, 255})</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.longname] = (Pg_1_qds_Bin_Indicator_2_v1)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.heith] = (32)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.weigth] = (50)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.poxX] = (352)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.poxY] = (116)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.valuealignment] = (Left)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.value_0] = (Off)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.value_1] = (On)</li>\n" + " </ul>\n" + " <li>Pg_1_qds_Bin_Indicator_3</li>\n" + " <ul>\n" + " <li>[QDSConsistency.report.field.logicIndicator.descriptionalignment] = (Right)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.descriptiontextcolor] = (Color {0, 0, 0, 255})</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.isdescriptiondisplayed] = (true)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.descriptionfontfamily] = (Arial)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.descriptionfontsize] = (11 pt)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.descriptionfontstyle] = (Normal)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.descriptionfontposition] = (LEFT)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.descriptiontext] = (v1)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.backgroundcolor] = (Color {238, 238, 238, 255})</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.digitnumber] = (8)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.widgetfont] = (FONT1)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.shortname] = (Pg_1_qds_Bin_Indicator_3)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.precision] = (2)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.widgetuserfontfamily] = (Arial)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.widgetuserfontsize] = (11 pt)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.widgetuserfontstyle] = (NORMAL)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.dynamicbackgroundcolor] = (Color {238, 238, 238, 255})</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.longname] = (Pg_1_qds_Bin_Indicator_3_v1)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.heith] = (32)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.weigth] = (50)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.poxX] = (446)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.poxY] = (187)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.valuealignment] = (Left)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.value_0] = (Off)</li>\n" + " <li>[QDSConsistency.report.field.logicIndicator.value_1] = (On)</li>\n" + " </ul>\n" + " </ul>\n" + " <p><em>Analog indicator :</em></p>\n" + " <ul>\n" + " <li>Pg_1_qds_Ana_Indicator_1</li>\n" + " <ul>\n" + " <li>[QDSConsistency.report.field.analogIndicator.descriptionalignment] = (Right)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.descriptiontextcolor] = (Color {0, 0, 0, 255})</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.isdescriptiondisplayed] = (true)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.descriptionfontfamily] = (Arial)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.descriptionfontsize] = (11 pt)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.descriptionfontstyle] = (Normal)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.descriptionfontposition] = (LEFT)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.descriptiontext] = (v0)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.backgroundcolor] = (Color {238, 238, 238, 255})</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.digitnumber] = (8)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.widgetfont] = (FONT1)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.shortname] = (Pg_1_qds_Ana_Indicator_1)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.precision] = (2)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.widgetuserfontfamily] = (Arial)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.widgetuserfontsize] = (11 pt)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.widgetuserfontstyle] = (NORMAL)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.dynamicbackgroundcolor] = (Color {238, 238, 238, 255})</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.longname] = (Pg_1_qds_Ana_Indicator_1_v0)</li>\n" + " <li>[QDSConsistency.report.field.analogIndicator.heith] = (32)</li>"; final Pattern pattern = Pattern.compile(regex); 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