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

Code Generator

Language

Generated Code

import Foundation let pattern = #"details:.*?(\/src\/.*?\.png\b)"# let regex = try! NSRegularExpression(pattern: pattern, options: .anchorsMatchLines) let testString = #""" '\u001b[1m\u001b[31m \u001b[1m● \u001b[1mregister page › register-automated › desktop › CONTROL\u001b[39m\u001b[22m\n\n Expected image to match or be a close match to snapshot but was 0.009980258828690502% different from snapshot (91 differing pixels).\n \u001b[1m\u001b[31mSee diff for details:\u001b[39m\u001b[22m \u001b[31m/src/pages/__image_snapshots__/__diff_output__/register-test-js-register-page-register-automated-desktop-control-1-diff.png\u001b[39m\n\u001b[2m\u001b[22m\n\u001b[2m \u001b[0m \u001b[90m 60 | \u001b[39m\u001b[0m\u001b[22m\n\u001b[2m \u001b[0m \u001b[90m 61 | \u001b[39m \u001b[36mconst\u001b[39m image \u001b[33m=\u001b[39m await page\u001b[33m.\u001b[39mscreenshot({ fullPage\u001b[33m:\u001b[39m isFullPage })\u001b[33m;\u001b[39m\u001b[0m\u001b[22m\n\u001b[2m \u001b[0m\u001b[31m\u001b[1m>\u001b[2m\u001b[39m\u001b[90m 62 | \u001b[39m expect(image)\u001b[33m.\u001b[39mtoMatchImageSnapshot({threshold\u001b[33m:\u001b[39m \u001b[35m0.3\u001b[39m})\u001b[33m;\u001b[39m\u001b[0m\u001b[22m\n\u001b[2m \u001b[0m \u001b[90m | \u001b[39m \u001b[31m\u001b[1m^\u001b[2m\u001b[39m\u001b[0m\u001b[22m\n\u001b[2m \u001b[0m \u001b[90m 63 | \u001b[39m })\u001b[33m;\u001b[39m\u001b[0m\u001b[22m\n\u001b[2m \u001b[0m \u001b[90m 64 | \u001b[39m\u001b[0m\u001b[22m\n\u001b[2m \u001b[0m \u001b[90m 65 | \u001b[39m \u001b[36mif\u001b[39m(experimentName \u001b[33m||\u001b[39m experiementVariationName) {\u001b[0m\u001b[22m\n\u001b[2m\u001b[22m\n\u001b[2m \u001b[2mat Object.toMatchImageSnapshot (\u001b[2msrc/command/getPageImageShot.js\u001b[2m:62:25)\u001b[2m\u001b[22m\n' """# 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