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
  • Match everything enclosed
    (?:...)
  • Capture everything enclosed
    (...)
  • 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

r"
"

Test String

Code Generator

Language

Generated Code

re = /(\v)/ str = 'line one&vellip; line twoimport { CustomCacheKey } from \'@layer0/core/router\' router.get(\'/some/path\', ({ cache }) => { cache({ key: new CustomCacheKey().addCookie(\'language\').addCookie(\'currency\'), // Other options... }) })import { CustomCacheKey } from \'@layer0/core/router\' router.get(\'/some/path\', ({ cache }) => { cache({ browser: { // Sets the cache-control: maxage=n header sent to the browser. To prevent the browser from caching this route // set maxAgeSeconds: 0 maxAgeSeconds: 0, // Sends a non-standard header `x-sw-cache-control: n` that you can use to control caching your service worker. // Note that service workers do not understand this header by default, so you would need to add code to your service // worker to support it serviceWorkerSeconds: 60 * 60, }, edge: { // Sets the TTL for a response in Layer0\'s edge cache maxAgeSeconds: 60 * 60 * 24, // Sets the amount of time a stale response will be served from the cache. When a stale response is sent, Layer0 // will simultaneously fetch a new response to serve subsequent requests. // Using stale-while-revalidate helps raise your effective cache hit rate to near 100%. staleWhileRevalidateSeconds: 60 * 60, // serve stale responses for up to 1 hour while fetching a new response // And many other options }, // Optionally customizes the cache key for both edge and browser key: new CustomCacheKey() .addBrowser() // Split cache by browser type .addCookie(\'some-cookie\'), // Split cache by some-cookie cookie }) })router.get(\'/scripts/:file\', ({ serveStatic }) => { serveStatic(\'path/to/scripts\', { permanent: true, // ensure that files are permanently accessible, even after a new version of the site has been deployed. exclude: [\'some-non-versioned-file.js\'], // you can exclude specific files from being served permanently. You should do this for any files that do not have a hash of the content in the name. }) })' # Print the match result str.match(re) do |match| puts match.to_s end

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 Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html