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 = #"intensity\"\s*:\s*\(\"\w+\"\s*:\s*(?<intensity>\d+)"# let regex = try! NSRegularExpression(pattern: pattern, options: .anchorsMatchLines) let testString = #""" ("data": ["from" : "2024-04-25T11: 30Z", "to": "2024-04-2512:00Z", "intensity": ("forecast": 152, "actual": null, "index": "moderate"}), ("from": "2024-04-25T12:002", "intensity": {"forecast": 152, "actual": null, "index": "moderate"}), ("from": "2024-04-25T12:30Z", "to": {"from": "2024-04-25T13:00Z", "to": "2024-04-25T12: 30Z", ("forecast": 164, "actual": null, "2024-04-2513: 30Z", "intensity": ("forecast": 154, "to": "2024-04-25T13: 002", "intensity": ("forecast": 154, "actual": null, "index": "actual": null, "index": "moderate"}), ("from": "2024-04-25T13:30Z*, "to": "2024-04-25T14:002", "moderate"}}, "intensity"： 04-25T14: 30Z", "to" : "index": "moderate"3}, ("from": "2024-04-25T14:002*, "to": "2024-04-25T14:30Z", "intensity": ("forecast": 166, "actual": null, "index": "moderate"}), ("from": " 2024-04-25T15:00Z" "actual": nu11, "index" "intensity": {"forecast": 170, "actual": null, "index": "moderate"}), {"from": "2024-04-2515: 00Z", 2024- "to" : "moderate"}), {"from": "2024-04-25T15:30Z", "to": "2024-04-25T16:00Z", "intensity": ("forecast": 175, "to": "2024-04-25T15: 30Z", "intensity": {"forecast": 172, "2024-04-25T16: 30Z", "index": "moderate"}}, ("from": "2024-04-25T17:00Z", "to": "intensity": ("forecast": 177, "actual": null, "index": "moderate"?), ("from": "2024-04-2516: 302", "actual" : nu11, "index" "moderate"}}, ("from": "2024-04-2516: 00Z", "to": "2024-04-25T17:002", "intensity": ("forecast": 179, "actual": null, 2024-04-2517: 30Z", "intensity": ("forecast": 181, "actual": null, 25T18:00Z", "intensity": ("forecast": 184, "index": "moderate"}}, {"from": "2024-04-25T17: 30Z", "actual": null, "index": "moderate"}), ("from": "2024-04-25T18:002", "to": "2024-04-25T18: 30Z", "to": "2024-04- "moderate"}}, ("from": "2024-04-2518: 30Z", "to": "2024-04-25T19:002", "intensity": ("forecast": 187, "actual": null, "intensity": ("forecast": 190, "actua1": nul1, "index": "index": "high"}}, ("from": "intensity": {"forecast": 193, "actual": null, "index": "2024-04-25T19: 00Z", "to": "2024-04-25T19: 30Z" "high"}}, ("from": "2024-04-25T19:30Z", "to": "2024-04-25T20:00Z", "intensity": {"forecast": 194, "2024-04-2520: 00Z", "to": "2024-04-25T20:30Z", "intensity": {"forecast": 195, "actual": null, "index": "high"3}, ("from": "2024-04-25T20:30Z", "actual": null, "index": "high")}, ("from": "2024-04-25T21:00Z", "intensity": ("forecast": 198, "actual": null, "index": "high"'), ("from": "2024-04-25T21: 002", "2024-04-25T22: 00Z", "intensity": {"forecast": 187, "actual": null, "to": "2024-04-25T21: 30Z", "intensity": {"forecast": 196, 'actual": null, "index": "high"}}, {"from": "2024-04-25T21:302" "to" "index": "moderate"}}, ("from": "2024-04-25T22:00Z", "to": "2024-04-25T22: 30Z", "intensity": ("forecast": 181, "actual": null, "index": "moderate"}}, {"from": "2024-04-25T22:30Z", "to": "2024-04-25T23:002", "intensity": ("forecast": 180, "actual": null, "index' moderate"｝｝，｛"from"： 25T23:30Z", "intensity": {"forecast": 172, "actual": null, "index": "moderate"}}, {"from": "2024-04-25T23: 30Z", "2024-04-25T23:002", "to": " 2024-04- "moderate"}}, {"from": "2024-04-26T00:00Z", "to": "2024-04-2600: 30Z", "intensity": ("forecast": 150, "to": "2024-04-2600: 00Z", "intensity": ("forecast": 150, "actual": null, "index": "actual": null, "index": "moderate")}, ("from": "2024-04-26T00: 302", "to": "2024-04-26T01:00Z" "intensity": {"forecast": 149, "actual": null, "index": "moderate"}}, ("from": "2024-04-26T01:002", "to": "2024-04-26T01:30Z", "intensity": {"forecast": 149, "actual": null, "index": "moderate"}}, ... """# 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