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

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"(?m)^hotma.*(om|cm|co|et)$|^hotmail\.com[^\.].*$|^hotmail$|^h(to)?mail\.com").unwrap(); let string = "SQL Expression hotmail.es hotmail.co.kr hotmail.co.uk hotmail.com.tw hotmail.com hotmail hotmailcom htomail.com hmail.com hotmai.com hotmail.cm hotmail.net hotmailc.om hotmaol.com homail.com hotmail.co hotmail.comahmedshakirny hotmail.com hotmail hotmailcom htomail.com hotmail.es hotmail.co.kr hotmail.co.uk hmail.com hotmai.com hotmail.cm hotmail.net hotmailc.om hotmaol.com homail.com hotmail.co hotmail.comahmedshakirny hotmail.comc hotmail.comi hotmail.om hoymail.com hitmail.com hjotmail.com hormail.com hotgmail.com hotmaii.com hotmail..com hotmail..comn hotmail.com.lowercaseletter hotmail.com.tw hotmail.comgeorge4nyy hotmail.comjehan.nizam09 hotmail.commn hotmail.comn hotmail.comorgmail.com hotmail.comorvince1812 hotmail.con hotmail.conm hotmail.corp hotmail.vom hotmail.xom hotmain.com hotmaiul.com hotmmail.com hpotmail.com "; // 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/