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)^(["']?)(\$?([0-9]{1,3},([0-9]{3},?)*[0-9]{3}|[0-9]{1,3})((.[0-9]{0,3})[0-9]{0,10})?)\1$"#).unwrap(); let string = "123456 123. . .123 123.154574 .545.4584 +1454 +487.54587 -54587.7487 .1225- .456+ 454.4+ 454.455874 45.45745687687.5678 45,547 45,5 ,154567891021 0,154567891021 123,1023458748 4546587,54587867 578,4 0 .123 0.00145 0.0 012345678910 1,345.154 4,330,234.34 5.545445454 3,023,123.34 12.1 5,356.12345678910 1.20 1.01 0.52 125.30 158,265.36 100,100,100,123,125,568,000.00 \"\" '' \"1\" '1' \"123\" '123' \"123.1\" '0' \"123.12345647891\" \"19,741.24\" 1234567891023154546574568768767866876767676876584764646546546465465464564564.240 \"191741.240\""; // 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/