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

/
/
gm

Test String

Code Generator

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{1,}\\[Documentation]\\s*(.*)$|^\\s{1,}\\.{3}\\s*(.*)$"; final String string = "\n" + "${DISPLAY_LINE1} 0 #TARIFF Display\n" + "${DISPLAY_LINE2} 1 #EXTRAS Display\n" + "${DISPLAY_LINE3} 2 #FARE Display\n\n" + "@{TEST_SCREENS_WITH_TIMEOUT} ShowDesc ShowOsAndCountryCode ShowSW ShowSerial\n" + "... Checksum_PPSU Checksum_BPSU Checksum_LPSU Checksum_GPSU Checksum_AEPS Checksum_FEPS Checksum_GPAR\n" + "... Datetime_Clock Datetime_DDMM Datetime_Year\n" + "... ShowHWRevBaseboard ShowHWRevSOM Digio LVTL_Info\n" + "... TestMeasure_WDZ TestMeasure_SEC TestMeasure_MET TestMeasure_SPD\n\n" + "@{TEST_SCREENS_WITHOUT_TIMEOUT} DisplayTest DisplaySettings Temperature\n\n" + "@{CHECKSUM_SCREENS} Checksum_PPSU Checksum_BPSU Checksum_LPSU\n\n" + "*** Keywords ***\n" + "Program Version contain\n" + " [Documentation] Read out program version and compare it with ${PROGARMM_VERSION}\n" + " ... Comparison is done with \"Should Contain\" which is equal to Pythons \"in\" operator,\n" + " ... it checks if ${PROGARMM_VERSION} is a substring of display content.\n" + " ... Examples: Display content is \"P.ITM30\"\n" + " ... Should Contain P.ITM30 ITM30 => PASS\n" + " ... Should Contain P.ITM30 ITM => PASS\n" + " ... Should Contain P.ITM30 I => PASS\n" + " ... Should Contain P.ITM30 ITM40 => FAIL\n\n" + " [Arguments] ${PROGARMM_VERSION}\n\n" + " Fail if not on measure mode screen ShowOsAndCountryCode\n" + " @{disp} = Read display in measure mode\n" + " Should Contain @{disp}[${DISPLAY_LINE3}] ${PROGARMM_VERSION} Program version not found: ${PROGARMM_VERSION}\n\n\n" + "Tarif EPS is\n" + " [Documentation] Read out tarif EPS and compare it with ${TARIF_EPS}\n" + " ... Comparison is done with \"Should be equal\"\n" + " [Arguments] ${TARIF_EPS}\n\n" + " Fail if not on measure mode screen Checksum_AEPS\n" + " @{disp} = Read display in measure mode\n" + " ${disp_traf_eps} = Catenate SEPARATOR= @{disp}[${DISPLAY_LINE1}] @{disp}[${DISPLAY_LINE3}]\n" + " ${disp_traf_eps} = Replace String ${disp_traf_eps} . ${EMPTY}\n\n" + " Should be equal ${disp_traf_eps} ${TARIF_EPS} Tarif EPS is not equal\n\n\n" + "Release Date contain\n" + " [Documentation] Read out program version and compare it with ${RELEASE_DATE}\n" + " ... Comparison is done with \"Should Contain\" which is equal to Pythons \"in\" operator.\n" + " ... For more information about the in-operator read Program Version contain - Keyword\n\n" + " [Arguments] ${RELEASE_DATE}\n\n" + " Fail if not on measure mode screen ShowSW\n" + " @{disp} = Read display in measure mode\n" + " Should Contain @{disp}[${DISPLAY_LINE3}] ${RELEASE_DATE} Release date not found: ${PROGRAM_VERSION}\n\n\n" + "Checksum is not blinking\n" + " [Documentation] Check if checksums displayed in MEASURE MODE does blinking\n\n" + " [Arguments] ${CHECKSUM_SCREEN}\n\n" + " Fail if not on measure mode screen ${CHECKSUM_SCREEN}\n"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); 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