Regular Expressions 101

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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

/
/
gmx

Test String

Code Generator

Language

Generated Code

const regex = /(?: ^ \s* (?<host>[\w-\.]*) \s* (?<rectype>\w*) \s* (?<value>[\w\.-].*) \s*$ )/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('(?: ^ \\s* (?<host>[\\w-\\.]*) \\s* (?<rectype>\\w*) \\s* (?<value>[\\w\\.-].*) \\s*$ )', 'gm') const str = `> ls -d midlandls.pncint.net [pasum60ad02.pncint.net] midlandls.pncint.net. SOA vasan60ad03.pncint.net ip.address.request.pncbank.com. (562550790 10800 3600 1209600 60) midlandls.pncint.net. NS vaash60ad04.pncint.net midlandls.pncint.net. NS pasum60ad11.pncint.net midlandls.pncint.net. NS pasum60ad01.pncint.net midlandls.pncint.net. NS pasum60ad02.pncint.net arcs-msmq CNAME weka357w.prod.pncint.net bar-rpt CNAME wbar303a.prod.pncint.net Bin CNAME services-gf2.midlandls.pncint.net cigna-msmq CNAME welm350w.prod.pncint.net citigroup-msmq CNAME welm352w.prod.pncint.net Cwm CNAME services-gf2.midlandls.pncint.net Cwm-app CNAME services-gf2.midlandls.pncint.net cwm-rpt CNAME wcwm316a.prod.pncint.net dbank-msmq CNAME welm344w.prod.pncint.net egs CNAME egs-gf0.midlandls.pncint.net egs-gf0 A 10.15.5.238 egs-gf1 A 10.38.5.238 egs-snat-gf0 A 10.15.7.238 egs-snat-gf1 A 10.38.7.238 eka CNAME services-gf2.midlandls.pncint.net elm CNAME services-gf2.midlandls.pncint.net fdic-msmq CNAME welm358w.prod.pncint.net genworth-msmq CNAME welm365w.prod.pncint.net icsg-msmq CNAME welm375w.prod.pncint.net iru CNAME services-gf2.midlandls.pncint.net iru-rpt CNAME wiru307a.prod.pncint.net mat CNAME services-gf2.midlandls.pncint.net mat-app CNAME services-gf2.midlandls.pncint.net mat-rpt CNAME wmat302a.prod.pncint.net mde CNAME services-gf2.midlandls.pncint.net mde-internet CNAME services-gf2.midlandls.pncint.net mfn CNAME services-gf2.midlandls.pncint.net mfn-app CNAME services-gf2.midlandls.pncint.net mfn-rpt CNAME wmfn318a.prod.pncint.net mis CNAME services-gf2.midlandls.pncint.net mis-app CNAME services-gf2.midlandls.pncint.net mis-rpt CNAME wmis308a.prod.pncint.net mls-msmq CNAME weka353w.prod.pncint.net mvm CNAME services-gf1.midlandls.pncint.net mvm-rpt CNAME wmvm302a.prod.pncint.net pii CNAME services-gf2.midlandls.pncint.net pnc-msmq CNAME weka373w.prod.pncint.net pnclms-msmq CNAME weka349w.prod.pncint.net rdt CNAME services-gf1.midlandls.pncint.net services-gf1 A 10.26.64.229 services-gf2 A 10.28.8.229 services-snat-gf1 A 10.26.68.249 services-snat-gf2 A 10.28.12.227 wdunlop-msmq CNAME welm31bw.prod.pncint.net wlm CNAME services-gf2.midlandls.pncint.net wlm-app CNAME wwlm305w.prod.pncint.net wlm-rpt CNAME wwlm306a.prod.pncint.net midlandls.pncint.net. SOA vasan60ad03.pncint.net ip.address.request.pncbank.com. (562550790 10800 3600 1209600 60) `; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } // The result can be accessed through the `m`-variable. m.forEach((match, groupIndex) => { console.log(`Found match, group ${groupIndex}: ${match}`); }); }

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 JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions