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

/
/
gi

Test String

Code Generator

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"(?i)(?:(?:(\d*(?:\d*(?:.?,?)*?)*?)(.?|,?)(\d*)) ?(k|m|g|c|d|p)?(mi|bbl.|cu.|doz.|fl.? ?oz|F|ft|gal|gr|in|k|lb|mph|n.m|oz|pt|qt|sq|rpm|tablespoon|teaspoon|tbsp|tsp|td|l |m|m|b|g|kl|l |C |g|m|mt|w)(?:\/?(h|s|m)?).? *?(?:\^ *?(\d+))?)(?= |\n|\r)").unwrap(); let string = ".05 ml 50 km 30 cm^23 12 cm 12.000.000,3 ml 12,000 ml 12,000,123.3 ml 12 km/h 12,000,123,312 ML 0.5 // This is a comment line. It is for human use only and is ignored by the Objective-C compiler. NSString *myString; int i = 0; NSString *myString = @\"This is a //valid// string\"; //... followed by a single line comment #ifndef// begin definition of pi #define SOME_CONSTANT 3.14 // pi #endif // end definition of pi NSString *my_string = @\"Line1 \\ Line2\"; // Multine string NSString *g = myString; // Comment ... NSString *myString = @\"dsff; //fsdf\"; NSString *myString = @\"dsff\\\"; //fsdf\"; self.viewController.title = @\"sdfsdfs\" //sdfsdfsdf \\n \"sdfsdf\";"; // 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/