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
Processing...

Test String

Code Generator

Language

Generated Code

const regex = /^[\w\-\.]+@([\w-]+\.)+[\w-]{2,}\:[\S\-\.]+$/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('^[\\w\\-\\.]+@([\\w-]+\\.)+[\\w-]{2,}\\:[\\S\\-\\.]+$', 'gm') const str = `example@example.com:sdfswe12312 example@gmail.com:sdfswe12312 example@example.co.fr:sdfswe12312 example@example.co.uk:sdfswe12312 john@smith.org::sdfswe12312 0-day@bk.ru:nob0dy 0-fpavs98-ref13@mail.ru:ref123456789 0-frajer@gazeta.pl:forktest1221 0-gun@live.nl:bokto12 0-i@ulmb.com:aq1sw2 0-lens@gmail.com:43867799ABC 0-mentor@bol.com.br:102030wi 0-tomac-0@mail.ru:vjq1994 0.0.0.vadim.0.0.0@gmail.com:ValsV199I 0.0.0.web.host@yahoo.com:kZ1X1Vc1vT 0.00webhostjeff@gmail.com:p95donkey 0.03-3f@sapo.pt:SP@Q_]3w0BE&a-{ 0.0@fl-de.com:hggi123 0.0@live.com:sxh3321100 0.0_robert_0.0@live.com:robert1992 0.0asd123@163.com:sls26355`; // 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