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

/
/
g

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"<a\s*[^>]*?>(?![^<]*?All).*?<\/a>").unwrap(); let string = "<!DOCTYPE html> <html dir=\"ltr\" lang=\"en\" xml:lang=\"en\"> <div id=\"page\" class=\"container-fluid clearfix\"> <div id=\"page-content\" class=\"row-fluid\"> <div id=\"region-bs-main-and-pre\" class=\"span9\"> <div class=\"row-fluid\"> <section id=\"region-main\" class=\"span8 pull-right\"> <div role=\"main\"><span id=\"maincontent\"></span><div class=\"no-overflow\"><table cellspacing=\"0\" id=\"overview-grade\" class=\"flexible boxaligncenter generaltable\"><thead><tr><th class=\"header c0\" scope=\"col\">Course name<div class=\"commands\"></div></th><th class=\"header c1\" scope=\"col\">Grade<div class=\"commands\"></div></th></tr></thead><tbody><tr class=\"\" id=\"grade-report-overview-45567_r0\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r0_c0\"><a href=\"https://odtuclass.metu.edu.tr/course/user.php?mode=grade&amp;id=723&amp;user=45567\">[BIOL 107 Section 1] Concepts in Biology</a></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r0_c1\">-</td></tr><tr class=\"\" id=\"grade-report-overview-45567_r1\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r1_c0\"><a href=\"https://odtuclass.metu.edu.tr/course/user.php?mode=grade&amp;id=5153&amp;user=45567\">[CENG 230 All Sections] Introduction to C Programming</a></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r1_c1\">-</td></tr><tr class=\"\" id=\"grade-report-overview-45567_r2\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r2_c0\"><a href=\"https://odtuclass.metu.edu.tr/course/user.php?mode=grade&amp;id=3054&amp;user=45567\">[CENG 230 Section 7] Introduction to C Programming</a></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r2_c1\">-</td></tr><tr class=\"\" id=\"grade-report-overview-45567_r3\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r3_c0\"><a href=\"https://odtuclass.metu.edu.tr/course/user.php?mode=grade&amp;id=3538&amp;user=45567\">[ENG 101 Section 40] English for Academic Purposes I</a></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r3_c1\">37.25</td></tr><tr class=\"\" id=\"grade-report-overview-45567_r4\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r4_c0\"><a href=\"https://odtuclass.metu.edu.tr/course/user.php?mode=grade&amp;id=3208&amp;user=45567\">[FDE 101 Section 1] Introduction to Food Engineering</a></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r4_c1\">55.33</td></tr><tr class=\"\" id=\"grade-report-overview-45567_r5\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r5_c0\"><a href=\"https://odtuclass.metu.edu.tr/course/user.php?mode=grade&amp;id=5358&amp;user=45567\">[MATH 119 All Sections] Calculus with Analytic Geometry</a></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r5_c1\">-</td></tr><tr class=\"\" id=\"grade-report-overview-45567_r6\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r6_c0\"><a href=\"https://odtuclass.metu.edu.tr/course/user.php?mode=grade&amp;id=578&amp;user=45567\">[MATH 119 Section 15] Calculus with Analytic Geometry</a></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r6_c1\">-</td></tr><tr class=\"\" id=\"grade-report-overview-45567_r7\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r7_c0\"><a href=\"https://odtuclass.metu.edu.tr/course/user.php?mode=grade&amp;id=219&amp;user=45567\">[PHYS 105 Section 16] General Physics I</a></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r7_c1\">-</td></tr><h3>Courses I am taking</h3><br /><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r8\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r8_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r8_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r9\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r9_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r9_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r10\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r10_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r10_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r11\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r11_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r11_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r12\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r12_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r12_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r13\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r13_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r13_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r14\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r14_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r14_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r15\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r15_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r15_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r16\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r16_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r16_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r17\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r17_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r17_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r18\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r18_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r18_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r19\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r19_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r19_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r20\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r20_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r20_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r21\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r21_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r21_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r22\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r22_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r22_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r23\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r23_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r23_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r24\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r24_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r24_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r25\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r25_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r25_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r26\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r26_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r26_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r27\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r27_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r27_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r28\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r28_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r28_c1\"></td></tr><tr class=\"emptyrow\" id=\"grade-report-overview-45567_r29\"><td class=\"cell c0\" id=\"grade-report-overview-45567_r29_c0\"></td><td class=\"cell c1\" id=\"grade-report-overview-45567_r29_c1\"></td></tr></tbody></table></div></div> </section> </div> </div> </div> </div> </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/