Regular Expressions 101

Save & Manage Regex

  • Current Version: 2
  • Save & Share
  • Community Library

Flavor

  • PCRE2 (PHP)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java
  • .NET 7.0 (C#)
  • Rust
  • PCRE (Legacy)
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests
Sponsors
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]
  • Character class intersection
    [\w&&[^\d]]
  • 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
Processing...

Test String

Code Generator

Language

Generated Code

import Foundation let pattern = #"googletag\.defineSlot.*?'([^']*)'\);"# let regex = try! NSRegularExpression(pattern: pattern) let testString = #""" googletag.defineSlot('Lorem1', [300, 100], 'div-ad-1430201576110-0'); googletag.defineSlot('Lorem2', [300, 100], 'div-ad-1442774220958-0'); googletag.defineSlot('Lorem3', [300, 100], 'div-ad-1448024965037-0'); googletag.defineSlot('Lorem4', [290, 60], 'div-ad-1429688274462-0'); googletag.defineSlot('Lorem5', [300, 200], 'div-ad-1448279284710-0'); googletag.defineSlot('Lorem6', [728, 90], 'div-ad-1389610933954-2'); googletag.defineSlot('Lorem7', [728, 90], 'div-ad-1389610933954-4'); googletag.defineSlot('Lorem8', [300, 250], 'div-ad-1389610933954-0'); googletag.defineSlot('Lorem9', [300, 250], 'div-ad-1448278717664-0'); googletag.defineSlot('Lorem10',[300, 250] 'div-ad-1425381569546-1'); googletag.defineOutOfPageSlot('Lorem11','div-ad-1424524422308-0-oop1'); googletag.defineOutOfPageSlot('Lorem12','div-ad-1424524422308-0-oop2'); googletag.defineOutOfPageSlot('Lorem13','div-ad-1389610933954-0-oop4'); googletag.defineOutOfPageSlot('Lorem14','div-ad-1389610933954-0-oop5'); googletag.defineOutOfPageSlot('Lorem15','div-ad-1389610933954-0-oop6'); """# 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