Regular Expressions 101

Save & Share

  • Regex Version: ver. 2
  • 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 single character of: a, b, c or d
    [[ab][cd]]
  • 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
No Match

"
"

Test String

Code Generator

Language

Generated Code

import Foundation let pattern = #"\"app\":\s\{((.|\n)*)\"local\""# let regex = try! NSRegularExpression(pattern: pattern) let testString = #""" { "app": { "local": "True", "dependency_env": "dev" }, "engine": { "disable_jwt_check": "true", "jwt_private_key": "sph59tZqVrjqz3BiVUnXvKRgd6BxDkN2E+TAjy96wfASO4/5DGJIQlZvnNSt4H7wKLQ0b1J5AdNJ7315B9My6w==", "jwt_issuer": "https://hbgpmwapi-dev.kantar.com" }, "azure": { "app_id": "efe4d19e-880e-480e-8e0c-f86c9fd5872c", "app_key": "b1e5em8uILeqAI.0jt=zg[mJHSaaHKz:", "env": "dev", "storage_key": "pKhqboH2XDRpYNLco4vyPapHNd7Ao/BO28yFBD0ooSSn/828NLMfKkkzdrqUyeeA2312Y9xAix1T/YdAHkbZCw==", "storage_container": "marketingpressure", "storage_endpoint": "https://hbgenginestorage.blob.core.windows.net" }, "URL": { "main": "http://localhost:3838" } } """# let stringRange = NSRange(location: 0, length: testString.utf16.count) if let firstMatch = regex.firstMatch(in: testString, range: stringRange) { let result: [String] = (1 ..< firstMatch.numberOfRanges).map { (testString as NSString).substring(with: firstMatch.range(at: $0)) } print(result) } else { print("No matches were found.") }

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