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

/
/
gm

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?m).*(idMatches):\n(?s)(.+?)(Close: )(?s)(.+?)$`) var str = `<ENG6_6701> idMatches: Close: ENG6_6701 <ENG6_7211> idMatches: Close: ENG6_7211 <ENG6_4474> idMatches: 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"> 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"> 04\G\0\IFM_2017.30_App.CrashMonitor.CrashMonitor.CrashMonitor_Main.script:645: ENG6_4474 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"> 06\10\00\Crasmonitor\IFM_2017.30_App.CrashMonitor.CrashMonitor.CrashMonitor_Main.script:220: ENG6_4474 Close: ENG6_4474 <ENG6_4475> NOTE: it was needed to change the first \n for a \r` var substitution = "\t<\1>\n\t\t\2\t</\1>\n</\4>\n" fmt.Println(re.ReplaceAllString(str, substitution)) }

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 Golang, please visit: https://golang.org/pkg/regexp/