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

Substitution

Processing...

Code Generator

Language

Generated Code

import Foundation let pattern = #"^.*:\s+([A-Z].*)_(\D+)_(\d+).*"# let regex = try! NSRegularExpression(pattern: pattern, options: .anchorsMatchLines) let testString = #""" dog-Cf-Nox1: Porites_lobata_1381 49.126 572 275 8 1 564 1 564 0.0 563 dog-Cf-Nox1: Porites_australiensis_5912 48.776 572 277 8 1 564 1 564 0.0 560 dog-Cf-Nox1: Astreopora_sp_20372 48.776 572 276 9 1 564 1 563 0.0 555 dog-Cf-Nox1: Montastraea_cavernosa_106939 48.148 567 279 7 5 564 6 564 0.0 555 dog-Cf-Nox1: Seriatopora_hystrix_66126 50.000 554 262 7 18 564 19 564 0.0 553 dog-Cf-Nox1: Porites_australiensis_4812 46.946 573 287 6 1 564 1 565 0.0 553 dog-Cf-Nox1: Stylophora_pistillata_7748 49.009 555 268 7 17 564 18 564 0.0 550 dog-Cf-Nox1: Porites_lobata_724 46.435 575 289 7 1 564 1 567 0.0 548 dog-Cf-Nox1: Acropora_digitifera_16260 46.935 571 288 7 1 564 1 563 0.0 538 """# let stringRange = NSRange(location: 0, length: testString.utf16.count) let substitutionString = #"\1,\2,\3"# let result = regex.stringByReplacingMatches(in: testString, range: stringRange, withTemplate: substitutionString) 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