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)[^\s<>]+(?![^<]*>)").unwrap(); let string = "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Transitional//EN\" \"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd\"><html xmlns=\"http://www.w3.org/1999/xhtml\" xml:lang=\"en\" lang=\"en\"><head><meta http-equiv=\"Content-Type\" content=\"text/html;\" /><title>Email Newsletter</title></head><body style=\"font-family: Helvetica, Arial, sans-serif; font-size: 12px\"> <p><span style=\"font-size:14px;\"><span style=\"font-family:arial,helvetica,sans-serif;\">Hi %%first_name%% - hope you can join us!<br> <br> <a href=\"https://xfinityflowershow.rsvpify.com/\"><img alt=\"\" border=\"0\" height=\"525\" src=\"http://go.pardot.com/l/292992/2019-02-26/3yvjz3/292992/83766/FlowerShow_Invite_V4.jpg\" style=\"height: 525px; width: 700px; border-width: 0px; border-style: solid;\" width=\"700\"></a><br> <br> Regards,<br> %%user_name%%<br> %%user_email%%<br> Comcast</span></span><br> <br> <br> <br> <br> <br> <br> <span style=\"font-size:10px;\"><span style=\"font-family:arial,helvetica,sans-serif;\">If&nbsp;you have received this communication in error or would like to unsubscribe, please&nbsp;click&nbsp;<a href=\"%%unsubscribe%%\">here</a>.&nbsp;</span></span></p> </body></html>"; // 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/