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

/
/
gmx

Test String

Code Generator

Language

Generated Code

import Foundation let pattern = #""" (?<!\S)(?P<set> (?:(?P<a>A) | (?P<b>B) | (?P<c>C)) (?: (?(a) (?!A)) (?(b) (?!B)) (?(c) (?!C)) (?&set) )? )\s """# let regex = try! NSRegularExpression(pattern: pattern, options: [.anchorsMatchLines, .allowCommentsAndWhitespace]) let testString = #""" ABC ACB AB AC BAC BCA BA BC CAB CBA CA CB A B C AA BB CC ABD ACD BAD BCD CAD CBD AAA AAB ABA BAA AAC ACA CAA BBB BBA BAB ABB BBC BCB CBB CCC CCA CAC ACC CCB CBC BCC ABCA ABCB ABCC ABCX ABCY ABCZ ACBA ACBB ACBC ACBX ACBY ACBZ BACA BACB BACC BACX BACY BACZ BCAA BCAB BCAC BCAX BCAY BCAZ CABA CABB CABC CABX CABY CABZ CBAA CBAB CBAC CBAX CBAY CBAZ """# 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