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

import Foundation let pattern = #"^([\+-]?\d{4}(?!\d{2}\b))((-?)((0[1-9]|1[0-2])(\3([12]\d|0[1-9]|3[01]))?|W([0-4]\d|5[0-2])(-?[1-7])?|(00[1-9]|0[1-9]\d|[12]\d{2}|3([0-5]\d|6[1-6])))([T\s]((([01]\d|2[0-3])((:?)[0-5]\d)?|24\:?00)([\.,]\d+(?!:))?)?(\17[0-5]\d([\.,]\d+)?)?([zZ]|([\+-])([01]\d|2[0-3]):?([0-5]\d)?)?)?)?$"# let regex = try! NSRegularExpression(pattern: pattern, options: .anchorsMatchLines) let testString = #""" http://www.pelagodesign.com/blog/2009/05/20/iso-8601-date-validation-that-doesnt-suck/ 2009-12T12:34 2009 2009-05-19 2009-05-19 20090519 2009123 2009-05 2009-123 2009-222 2009-001 2009-W01-1 2009-W51-1 2009-W511 2009-W33 2009W511 2009-05-19 2009-05-19 00:00 2009-05-19 14 2009-05-19 14:31 2009-05-19 14:39:22 2009-05-19T14:39Z 2009-W21-2 2009-W21-2T01:22 2009-139 2009-05-19 14:39:22-06:00 2009-05-19 14:39:22+0600 2009-05-19 14:39:22-01 20090621T0545Z 2007-04-06T00:00 2007-04-05T24:00 Added Feb 19 2010: 2010-02-18T16:23:48.5 2010-02-18T16:23:48,444 2010-02-18T16:23:48,3-06:00 2010-02-18T16:23.4 2010-02-18T16:23,25 2010-02-18T16:23.33+0600 2010-02-18T16.23334444 2010-02-18T16,2283 2009-05-19 143922.500 2009-05-19 1439,55 And here are some of the strings that the validator should not match (ie. reject): 200905 2009367 2009- 2007-04-05T24:50 2009-000 2009-M511 2009M511 2009-05-19T14a39r 2009-05-19T14:3924 2009-0519 2009-05-1914:39 2009-05-19 14: 2009-05-19r14:39 2009-05-19 14a39a22 200912-01 2009-05-19 14:39:22+06a00 Added Feb 19 2010: 2009-05-19 146922.500 2010-02-18T16.5:23.35:48 2010-02-18T16:23.35:48 2010-02-18T16:23.35:48.45 2009-05-19 14.5.44 2010-02-18T16:23.33.600 2010-02-18T16,25:23:48,444 """# 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