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
  • Match everything enclosed
    (?:...)
  • Capture everything enclosed
    (...)
  • 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

import Foundation let pattern = #"(--([A-z\-]*?):(?<!--rgb:)).*?;"# let regex = try! NSRegularExpression(pattern: pattern, options: .anchorsMatchLines) let testString = ##""" --color-primary: #0017a8; --color-primary--rgb: #{hexToRGB(color-primary)}; --variablename: blabla blablabla; --color-secondary: #0631ff; --color-secondary--rgb: #{hexToRGB(color-secondary)}; --color-tertiary: #00ffe0; --color-tertiary--rgb: #{hexToRGB(color-tertiary)}; --color-green-dark: #257426; --color-green-dark--rgb: #{hexToRGB(color-green-dark)}; --font-family: TTCommons, Helvetica, Arial, sans-serif; --transition: 0.3s ease; --box-shadow: 0 0 12px 0 rgba(0, 0, 0, 0.3); """## let stringRange = NSRange(location: 0, length: testString.utf16.count) let substitutionString = ##"$1 #{$$$2};"## let result = regex.stringByReplacingMatches(in: testString, range: stringRange, withTemplate: substitutionString) print(result)

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 Swift 5.2, please visit: https://developer.apple.com/documentation/foundation/nsregularexpression