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

@
@
xmg

Test String

Code Generator

Language

Generated Code

import Foundation let pattern = ##""" ^ # Possible: http:// # https:// # // (?:(?:https?:)?//)? # Possible: www. # m. (?:(?:www|m)\.)? # Possible: youtube.com # youtube-nocookie.com # youtu.be (?:(?:youtube(?:-nocookie)?\.com|youtu.be))? # Possible: /[a-zA-Z0-9_-]+?v= # /embed/ # /v/ (?:/(?:[\w-]+\?v=|embed/|v/)?)? # Possible: oembed?url=...v= (?:oembed\?url=.*\?v%3D)? # TOKEN: [a-zA-Z0-9_-] ([\w-]{11}) # Possible: Anything not space+ (?:\S+)? # EOF pattern with x(PCRE_EXTENDED) flag: $ """## let regex = try! NSRegularExpression(pattern: pattern, options: [.anchorsMatchLines, .allowCommentsAndWhitespace]) let testString = #""" Matches: DFYRQ_zQ-gk https://www.youtube.com/watch?v=DFYRQ_zQ-gk https://www.youtube.com/watch?v=DFYRQ_zQ-gk youtube.com/watch?v=DFYRQ_zQ-gk https://www.youtube.com/watch?v=DFYRQ_zQ-gk https://www.youtube.com/v/DFYRQ_zQ-gk?version=3&autohide=1 https://youtu.be/DFYRQ_zQ-gk https://www.youtube.com/watch?v=DFYRQ_zQ-gk&feature=featured https://www.youtube.com/watch?v=DFYRQ_zQ-gk http://www.youtube.com/watch?v=DFYRQ_zQ-gk //www.youtube.com/watch?v=DFYRQ_zQ-gk www.youtube.com/watch?v=DFYRQ_zQ-gk https://youtube.com/watch?v=DFYRQ_zQ-gk http://youtube.com/watch?v=DFYRQ_zQ-gk //youtube.com/watch?v=DFYRQ_zQ-gk youtube.com/watch?v=DFYRQ_zQ-gk https://m.youtube.com/watch?v=DFYRQ_zQ-gk http://m.youtube.com/watch?v=DFYRQ_zQ-gk //m.youtube.com/watch?v=DFYRQ_zQ-gk m.youtube.com/watch?v=DFYRQ_zQ-gk https://www.youtube.com/v/DFYRQ_zQ-gk?fs=1&hl=en_US http://www.youtube.com/v/DFYRQ_zQ-gk?fs=1&hl=en_US //www.youtube.com/v/DFYRQ_zQ-gk?fs=1&hl=en_US www.youtube.com/v/DFYRQ_zQ-gk?fs=1&hl=en_US youtube.com/v/DFYRQ_zQ-gk?fs=1&hl=en_US https://www.youtube.com/embed/DFYRQ_zQ-gk?autoplay=1 https://www.youtube.com/embed/DFYRQ_zQ-gk http://www.youtube.com/embed/DFYRQ_zQ-gk //www.youtube.com/embed/DFYRQ_zQ-gk www.youtube.com/embed/DFYRQ_zQ-gk https://youtube.com/embed/DFYRQ_zQ-gk http://youtube.com/embed/DFYRQ_zQ-gk //youtube.com/embed/DFYRQ_zQ-gk youtube.com/embed/DFYRQ_zQ-gk https://www.youtube-nocookie.com/embed/DFYRQ_zQ-gk?autoplay=1 https://www.youtube-nocookie.com/embed/DFYRQ_zQ-gk http://www.youtube-nocookie.com/embed/DFYRQ_zQ-gk //www.youtube-nocookie.com/embed/DFYRQ_zQ-gk www.youtube-nocookie.com/embed/DFYRQ_zQ-gk https://youtube-nocookie.com/embed/DFYRQ_zQ-gk http://youtube-nocookie.com/embed/DFYRQ_zQ-gk //youtube-nocookie.com/embed/DFYRQ_zQ-gk youtube-nocookie.com/embed/DFYRQ_zQ-gk https://youtu.be/DFYRQ_zQ-gk?t=120 https://youtu.be/DFYRQ_zQ-gk http://youtu.be/DFYRQ_zQ-gk //youtu.be/DFYRQ_zQ-gk youtu.be/DFYRQ_zQ-gk https://www.youtube.com/HamdiKickProduction?v=DFYRQ_zQ-gk https://www.youtube.com/oembed?url=http%3A//www.youtube.com/watch?v%3DDFYRQ_zQ-gk&format=json No Matches: Hello https://www.youtube.com/watch?v=nzj7Wg4DAbs world http://youtu.be/ youtube is cool youtube/cCnrX1w5luM http://youtube/cCnrX1w5luM """# let stringRange = NSRange(location: 0, length: testString.utf16.count) let matches = regex.matches(in: testString, range: stringRange) var result: [[String]] = [] for match in matches { var groups: [String] = [] for rangeIndex in 1 ..< match.numberOfRanges { let nsRange = match.range(at: rangeIndex) guard !NSEqualRanges(nsRange, NSMakeRange(NSNotFound, 0)) else { continue } let string = (testString as NSString).substring(with: nsRange) groups.append(string) } if !groups.isEmpty { result.append(groups) } } 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