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

@"
"
g

Test String

Code Generator

Generated Code

import Foundation let pattern = ##"\(\?\(DEFINE\)(?<definition>(?<=(?:[^\\](?:\\\\)+)|[^\\])\(\?\<(?<name>[\w-[0-9]]\w*?)\>(?<content>(?#internals shallow)(?:(?:(?<=(?:[^\\](?:\\\\)+)|[^\\])\[(?:(?<=(?:[^\\](?:\\\\)+)|[^\\])(?:\\\[|\\\])|[^\[\]])*(?<=(?:[^\\](?:\\\\)+)|[^\\])\])|(?:(?<=(?:[^\\](?:\\\\)+)|[^\\])\(\?(?:\!|\=|\:|\<\!|\<\=)(?#internals deep)(?:(?<=(?:[^\\](?:\\\\)+)|[^\\])(?:\\\(|\\\)|\\\[|\\\])|[^\(\)\[\]])+(?<=(?:[^\\](?:\\\\)+)|[^\\])\))|(?:(?<=(?:[^\\](?:\\\\)+)|[^\\])(?:\\\(|\\\)|\\\[|\\\])|[^\(\)\[\]]))+)(?<=(?:[^\\](?:\\\\)+)|[^\\])\))*(?<=(?:[^\\](?:\\\\)+)|[^\\])\)"## let regex = try! NSRegularExpression(pattern: pattern) let testString = ##"(?(DEFINE)(?<internal_name_char_s>[^\x85\n\r\v\t\\\/\:\*\"\?\<\>\|])(?<external_filesc_name_char_s>[^\x85\n\r\v\t\\\/\:\*\"\?\<\>\|\s])(?<external_folderesc_name_char_s>[^\x85\n\r\v\t\\\/\:\*\"\?\<\>\|\s\.])(?<folder_name_s>\g'external_filesc_name_char_s'\g'internal_name_char_s'{1,258}\g'external_filesc_name_char_s'|\g'external_folderesc_name_char_s'\g'external_filesc_name_char_s'|\g'external_filesc_name_char_s'\g'external_folderesc_name_char_s'|\g'external_folderesc_name_char_s')(?<extension_char_s>[a-z0-9])(?<extension_s>\g'extension_char_s'{1,260})(?<file_name_s>(?:\g'external_filesc_name_char_s'\g'internal_name_char_s'{1,258}\g'external_filesc_name_char_s'|\g'external_filesc_name_char_s'{1,2})(?=\.\g'extension_s'\Z))(?<ipv4_number_s>(?:[12]\d\d)|(?:\d\d)|(?:\d))(?<ipv4_s>(?:\g'ipv4_number_s'\.){3}\g'ipv4_number_s'(?:\:\d+)?)(?<named_drive_root_s>[a-z]\:\/)(?<file_protocol_root_s>file\:\/\/\/\g'named_drive_root_s')(?<smb_root_s>\/\/)(?<hyper_text_root_s>https?\:\/\/))(?#definition is complete)\A(?!\Z)(?<all_until_last_name>(?<root>(?<fixed_root>\/|\g'named_drive_root_s'|\g'file_protocol_root_s'|(?<remote_root>\g'smb_root_s'|\g'hyper_text_root_s')(?:(?<ipv4>\g'ipv4_s')(?:\/(?!\Z)|))?)|(?<relative_root>\.{1,2}\/(?:\.\.\/)*))?(?<body>(?:\g'folder_name_s'\/)*?))(?<last_folder_or_file_name>(?<file_full_name>(?<file_short_name>\g'file_name_s')\.(?:(?<shortcut_extension>lnk)|(?<remote_extension>url)|(?<general_extension>\g'extension_s'))(?!\/))|(?:(?<folder_name>\g'folder_name_s')\/?))?\Z"## 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