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

Substitution

Processing...

Code Generator

Language

Generated Code

import Foundation let pattern = #""_id[^,]*,\s*"# let regex = try! NSRegularExpression(pattern: pattern, options: .anchorsMatchLines) let testString = #""" json_file<- '{ "_id" : ObjectId( "539163d7bd350003" ), "login" : "vui", "id" : 369607, "avatar_url" : "https://avatars.mashupsusercontent.com/u/369607?", "gravatar_id" : "df8897ffebe16c5b0cd690925c63e190", "url" : "https://api.mashups.com/users/vui", "html_url" : "https://mashups.com/vui", "followers_url" : "https://api.mashups.com/users/vui/followers", "following_url" : "https://api.mashups.com/users/vui/following{/other_user}", "gists_url" : "https://api.mashups.com/users/vui/gists{/gist_id}", "starred_url" : "https://api.mashups.com/users/vui/starred{/owner}{/repo}", "subscriptions_url" : "https://api.mashups.com/users/vui/subscriptions", "organizations_url" : "https://api.mashups.com/users/vui/orgs", "repos_url" : "https://api.mashups.com/users/vui/repos", "events_url" : "https://api.mashups.com/users/vui/events{/privacy}", "received_events_url" : "https://api.mashups.com/users/vui/received_events", "type" : "User", "site_admin" : false, "org" : "amurath" }' """# let stringRange = NSRange(location: 0, length: testString.utf16.count) let substitutionString = #""# let result = regex.stringByReplacingMatches(in: testString, range: stringRange, withTemplate: substitutionString) 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