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

`
`
gm

Test String

Code Generator

Language

Generated Code

const regex = new RegExp('(?P<origin>(?P<protocol>http[s]?:)?\\/\\/(?P<host>[a-z0-9A-Z-_.]+))(?P<port>:\\d+)?(?P<path>[\\/a-zA-Z0-9-\\.]+)?(?P<search>\\?[^#\\n]+)?(?P<hash>#.*)?', 'gm') const str = `https://www.geeksforgeeks.org/lru-cache-implementation/#hastest?name=234ksldjfkl&sjkldf= https://developer.ibm.com/series/kubernetes-learning-path/ https://www.google.com/search?q=cannot+find+package+%22context%22+in+any+of%3A&oq=cannot+find+package+%22context%22+in+any+of%3A&aqs=chrome..69i57j0l5.205752j0j4&sourceid=chrome&ie=UTF-8#hello world https://myaccount.google.com/name?utm_source=google-account&utm_medium=web&pli=1&rapt=AEjHL4PXc8zLqgFQOXxYQRbdKJI8\\nyNq3u&name=rjl@1239015423#Kkn1HwudmOHSj7MpYAguZoOmrznrl0PF7hyLkZ17xFdrXToG5UDkMhO2bM1a6i5xw#path=234&sp=\\n`; // 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