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

/
/
i

Test String

Code Generator

Language

Generated Code

import Foundation let pattern = #"(\bByVal\b|\bByRef\b)? +(\w+)(?: +as +(\w+))?(?: *= *[\w"]+)? *[\)|,]?"# let regex = try! NSRegularExpression(pattern: pattern, options: .caseInsensitive) let testString = #" ByVal S_Random, ByVal S_Sign_JS, ByRef S_Ksc, ByRef HS_EkscEkakscn, ByRef intResult, ByVal strEKA, ByVal strNmLogon, ByVal StrNivelUsuario, ByVal lngIDConexao, ByVal strBanco, ByVal strAgencia, ByVal strConta, ByVal strTipoDePessoa, ByVal lngCodUsuario, ByVal lngContrato, ByRef LngRetCode, ByRef strErro, ByRef strErroTecnica, ByVal intIdCanal, ByVal strIPAddrCliente, ByVal strIPAddrServer, Optional ByRef S_PW, Optional ByRef S_PBE"# let stringRange = NSRange(location: 0, length: testString.utf16.count) if let firstMatch = regex.firstMatch(in: testString, range: stringRange) { let result: [String] = (1 ..< firstMatch.numberOfRanges).map { (testString as NSString).substring(with: firstMatch.range(at: $0)) } print(result) } else { print("No matches were found.") }

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