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

/
/
gmx

Test String

Code Generator

Generated Code

import Foundation let pattern = ##""" (?(DEFINE) (?# Date ) (?# Day ranges ) (?<d_day28>0[1-9]|1\d|2[0-8]) (?<d_day29>0[1-9]|1\d|2\d) (?<d_day30>0[1-9]|1\d|2\d|30) (?<d_day31>0[1-9]|1\d|2\d|3[01]) (?# Month specifications ) (?<d_month28>02) (?<d_month29>02) (?<d_month30>0[469]|11) (?<d_month31>0[13578]|1[02]) (?# Year specifications ) (?<d_year>\d+) (?<d_yearLeap>(?:\d*?(?:(?:(?!00)[02468][048]|[13579][26])|(?:(?:[02468][048]|[13579][26])00))|[48]00|[48])(?=\D|\b)) (?# Valid date formats ) (?<d_format> (?&d_day28)\/(?&d_month28)\/(?&d_year)| (?&d_day29)\/(?&d_month29)\/(?&d_yearLeap)| (?&d_day30)\/(?&d_month30)\/(?&d_year)| (?&d_day31)\/(?&d_month31)\/(?&d_year) ) (?# Time ) (?# Time properties ) (?<t_period12>(?i)[ap]m|[ap]\.m\.(?-i)) (?# Hours ) (?<t_hours12>0\d|1[01]) (?<t_hours24>[01]\d|2[0-3]) (?# Minutes ) (?<t_minutes>[0-5]\d) (?# Seconds ) (?<t_seconds>[0-5]\d) (?# Milliseconds ) (?<t_milliseconds>\d{3}) (?# Valid time formats ) (?<t_format> (?&t_hours12):(?&t_minutes):(?&t_seconds)(?:\.(?&t_milliseconds))?\ ?(?&t_period12)| (?&t_hours24):(?&t_minutes):(?&t_seconds)(?:\.(?&t_milliseconds))? ) (?# Datetime ) (?<dt_format>(?&d_format)\ (?&t_format)) ) \b(?&dt_format)\b """## let regex = try! NSRegularExpression(pattern: pattern, options: [.anchorsMatchLines, .allowCommentsAndWhitespace]) let testString = #""" 29/02/2016 23:10:59 - valid 29/02/2017 23:10:59 - invalid (not leap year) 30/03/2016 23:10:59 - valid """# 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