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]
  • Character class intersection
    [\w&&[^\d]]
  • 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
Processing...

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#"(?m)^(\+ *|- *)?((?!0+)\d*?|(?!0{2,})\d*?\.(?!0+)\d*?)('|")$|^(\+ *|- *)? *(?!0+)\d+?' *-? *(\d+?|\d*?\.\d*?)"$|^((\+ *|- *)?((?!0+)|0 )\d*? *(?!0+)\d+?\/(?!0+)\d+?('|"))$"#).unwrap(); let string = " - + - x 20'-4\" + 20' - 20' 20'3\" 20'-3\" 20' - 40\" -20'-20\" 20'00\" 20.45\" 20.45' 00.45' 00.45\" 00\" 00' +20' - 0.45\" 20' - .45\" .20'-4\" 0.30'-4\" 20' 20'P 20\" 20\"P 0.20' .20' a' b\" - 20 1/2' + 20 22/128\" 20 0/2\" 20 00/12' -1/2\" + 1/2' 0/2\" 00/22\" + 01/2\" 23 00/30' 23 12/03' 23 02/20\" 0 2/3' 00 2/3' - 11 2/3' 2 22' 2 22/03' 2 3/2 23 00/30 23 12/03 23 02/20 23/34\" 23/23.4\" asf sf\" "; // 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/