Regular Expressions 101

Save & Share

  • Regex Version: ver. 1
  • Update Regex
    ctrl+⇧+s
  • Save new Regex
    ctrl+s
  • Add to Community Library

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
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 = #""width"\s*:\s*(?'width'\d+).+?"height"\s*:\s*(?'height'\d+).+?"url"\s*:\s*\"(?'url'.+?)""# let regex = try! NSRegularExpression(pattern: pattern, options: .anchorsMatchLines) let testString = ##"<pre>#34;, "createdAt": "2018-07-30T13:33:21.373947"}, {"uid": "c442c352934545b183e16ce9aebd91cb", "width": 2048, "options": {"format": "R", "quality": 88}, "updatedAt": "2018-08-01T17:51:24.738232", "height": 2048, "size": 618478, "url": "https://media.sketchfab.com/urls/ea1adc30399045a2b101e16ba65a856f/dist/textures/a4291782af5f4ce39e637c89ec91fa9b/c442c352934545b183e16ce9aebd91cb.jpeg", "createdAt": "2018-08-01T17:51:25.334608"}, {"uid": "84275b9d01b54836893e355991288c2f", "width": 1024, "options": {"format": "R", "quality": 92}, "updatedAt": "2018-08-01T17:51:25.341010", "height": 1024, "size": 220485, "url": "https://media.sketchfab.com/urls/ea1adc30399045a2b101e16ba65a856f/dist/textures/a4291782af5f4ce39e637c89ec91fa9b/84275b9d01b54836893e355991288c2f.jpeg", "createdAt": "2018-08-01T17:51:25.451079"}, {"uid": "88897653dc004ded9faee4eaf2fa0373", "width": 512, "options": {"format": "R", "quality": 95}, "updatedAt": "2018-08-01T17:51:25.456671", "height": 512, "size": 83896, "url": "https://media.sketchfab.com/urls/ea1adc30399045a2b101e16ba65a856f/dist/textures/a4291782af5f4ce39e637c89ec91fa9b/88897653dc004ded9faee4eaf2fa0373.jpeg""## 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