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

/
/
g

Test String

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#"errorDescription\"\:\"(?<errorDescription>[^\"]+).+errorCode\"\:\"(?<errorCode>[^\"]+)"#).unwrap(); let string = "2016-10-25 12:33:31,926 [http-00000:13111-2] INFO [org.apache.cxf.interceptor.LoggingInInterceptor ?] Inbound Message ---------------------------- ID: 18 Response-Code: 200 Encoding: UTF-8 Content-Type: application/json;charset=UTF-8 Headers: {content-type=[application/json;charset=UTF-8], Date=[Tue, 25 Oct 2016 17:33:30 GMT], Expires=[Thu, 01 Jan 1970 00:00:00 GMT], Set-Cookie=[BrowserId=L8p9Eij0T4Sfp-INSP9zDw;Path=/;Domain=.salesforce;Expires=Sat, 24-Dec-2016 17:33:30 GMT], transfer-encoding=[chunked]} Payload: {\"responseCode\":\"201\",\"messageId\":\"704c8163-13d4-42b8-a684-94b9d23e849e\", \"lead\":[{\"responseCode\":\"201\",\"leadID\":null,\"errors\":[{\"errorField\":\"head\",\"errorDescription\":\"The value of email is invalid.\",\"errorCode\":\"Value_Invalid_E400\"},{\"errorField\":\"bestTimeToContact\",\"errorDescription\":\"The value of bestTimeToContact is invalid.\",\"errorCode\":\"Value_Invalid_E400\"}]}]} ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 2016-10-25 12:33:31,986 [http-000000:13111-2] INFO [org.apache.cxf.interceptor.LoggingOutInterceptor ?] Outbound Message --------------------------- ID: 17 Response-Code: 200 Content-Type: application/json Headers: {Content-Type=[application/json], Date=[Tue, 25 Oct 2016 17:33:31 GMT]} Payload: {\"errors\":[{\"errorCode\":\"Value_Invalid_E400\",\"errorDescription\":\"The value of email is invalid.\",\"errorField\":\"head\"},{\"errorCode\":\"Value_Invalid_E400\",\"errorDescription\":\"The value of bestTimeToContact is invalid.\",\"errorField\":\"bestTimeToContact\"}]} --------------------------------------"; // result will be an iterator over tuples containing the start and end indices for each match in the string let result = regex.captures_iter(string); for mat in result { println!("{:?}", mat); } }

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/