Regular Expressions 101

Save & Share

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

/
/
g

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

// include the latest version of the regex crate in your Cargo.toml extern crate regex; use regex::Regex; fn main() { let regex = Regex::new(r"(?'pair'(?'d'-)(?'lcv'\w+)(?'s'\s)(?'dol'\$)(?'o'\()(?'ucv'\w+)(?'c'\)))(?'es'\n?)").unwrap(); let string = "-solutionName $(SolutionName) -solutionAbbreviation $(SolutionAbbreviation) -projectName $(ProjectName) -projectAbbreviation $(ProjectAbbreviation) -environmentAbbreviation $(EnvironmentAbbreviation) -appServicePlanAbbreviation $(AppServicePlanAbbreviation) -logicAppAbbreviation $(LogicAppAbbreviation) -serviceBusNamespaceAbbreviation $(ServiceBusNamespaceAbbreviation) -serviceBusQueueAbbreviation $(ServiceBusQueueAbbreviation) -scanAppServicePlanLocation $(ScanAppServicePlanLocation) -scanAppServicePlanSKUName $(ScanAppServicePlanSKUName) -scanAppServicePlanSKUTier $(ScanAppServicePlanSKUTier) -scanAppServicePlanNumberOfWorkers $(ScanAppServicePlanNumberOfWorkers) -hockeyAppAPIUri $(HockeyAppAPIUri) -hockeyAppAPIAuthenticationTenant $(HockeyAppAPIAuthenticationTenant) -hockeyAppAPIAuthenticationAudience $(HockeyAppAPIAuthenticationAudience) -hockeyAppAPIAuthenticationClientId $(HockeyAppAPIAuthenticationClientId) -hockeyAppAPIAuthenticationSecret $(HockeyAppAPIAuthenticationSecret) -hockeyAppAPIPollingInterval $(HockeyAppAPIPollingInterval) -scanQueueNamespaceKind $(ScanQueueNamespaceKind) -scanQueueNamespaceSkuName $(ScanQueueNamespaceSkuName) -scanQueueNamespaceSkuTier $(ScanQueueNamespaceSkuTier) -scanQueueNamespaceLocation $(ScanQueueNamespaceLocation) -scanQueueNamespaceAuthorizationRulesLocation $(ScanQueueNamespaceAuthorizationRulesLocation) "; let substitution = "${pair}"; // result will be a String with the substituted value let result = regex.replace_all(string, substitution); println!("{}", 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 Rust, please visit: https://docs.rs/regex/latest/regex/