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

r'
'
gm

Test String

Code Generator

Language

Generated Code

const regex = new RegExp('COV2-([0-9]+)([\\s]+)([A-Z]+)', 'gm') const str = ` Name CDRH3 0 COV2-2997 ARGAIPPNSRAEIDY 1 COV2-3012 ARVLYDSSGFYNWFDP 2 COV2-2961 AAPYCSSISCNDGFDI 3 COV2-3025 AAPYCSSISCNDGFDI 4 COV2-2046 AKAHSTGHQYYYGMDV 5 COV2-2196 AAPYCSSISCNDGFDI 6 COV2-2901 ARSYDILTGYRDAFDI 7 COV2-2070 ARVGYSQGYYYYYMDV 8 COV2-2132 ARDFLRWHDL 9 COV2-2911 ARMSRGYNYAYTFDI 10 COV2-2098 VKGLFDWFPL 11 COV2-2108 AKGVDYGGKLAYFDS 12 COV2-2114 ARGRGYSNYGASYYMDV 13 COV2-2304 ARDPVWVDGELLSGGIPFDY 14 COV2-2078 ARVGVSGFKSGSNWYFDL 15 COV2-2299 ARDIDSGYDPTPVFDY 16 COV2-2351 ARRFYGPSSFDY 17 COV2-2318 ARGVVTYDY 18 COV2-2703 ARARGGYNWNFDY 19 COV2-2277 ARDVPTTVTAFTVFTY 20 COV2-2068 ARSYDILTGYRDAFDI 21 COV2-2504 ARVVVLGYGRPNNYYDGRNVWDY 22 COV2-2510 ARWGPDYGDYASNDY 23 COV2-2308 VKGLFDWFPL 24 COV2-2391 ARMRSGWPTHGRPDDF 25 COV2-2767 ARSYDILTGYRDAFDI 26 COV2-2113 ARDFLRWHDL 27 COV2-2290 ARMRSGWPTHGRPDDF 28 COV2-2130 TTAGSYYYDTVGPGLPEGKFDY 29 COV2-2050 ARVVVLGYGRPNNYYDGRNVWDY .. ... ... 355 COV2-2587 AHRLWFRDAFDI 356 COV2-2551 ASGPPYMATFSYYFDY 357 COV2-2481 ARGWFGELLKGTYWFDP 358 COV2-2029 ARPTAGAGGAFDI 359 COV2-2590 ARGRVGYVGSGSRGYYYYYDMDV 360 COV2-2408 ARVGGISPYYYYYYMDV 361 COV2-2565 ARGAASFDY 362 COV2-2641 AKSYNGNYYDAFDI 363 COV2-2449 ARASYNSNWSIGEYFRD 364 COV2-2619 ARVEGDWLLGGPYYHYYGMDV 365 COV2-2367 ARTSHYDSSGSYFEY 366 COV2-2343 ARVQRRRLDY 367 COV2-2270 AITYYYDSSGYWWDD 368 COV2-2187 ARGGATNFDY 369 COV2-2478 AKGIYYDIFMPLLD 370 COV2-2820 ARDQSQGAYILTGYRGYGMDV 371 COV2-2620 ARADTMVRGTYFEY 372 COV2-2171 ARLSGSSWDFDY 373 COV2-2583 ARGGIYYLVRGFIIGYYGMDV 374 COV2-2227 ARDQSQGAYILTGYRGYGMDV 375 COV2-2160 ARSTSGSYYYGMDV 376 COV2-2178 ARVGSSSWYFDY 377 COV2-2159 ARSTSGSYYYGMDV 378 COV2-2166 ARIGHFDSSGYYLDY 379 COV2-2224 AKDGSIAAADY 380 COV2-2214 ARIGHFDSSGYYLDY 381 COV2-2218 ARPYTGSYKSYMDV 382 COV2-2216 ARTSHYDSSGSYFEY 383 COV2-2175 ARLSGSSWDFDY 384 COV2-2183 ARADTMVRGTYFEY [385 rows x 2 columns] Name CDRH3 0 COV2-2997 ARGAIPPNSRAEIDY 1 COV2-3012 ARVLYDSSGFYNWFDP 2 COV2-2961 AAPYCSSISCNDGFDI 3 COV2-3025 AAPYCSSISCNDGFDI 4 COV2-2046 AKAHSTGHQYYYGMDV 5 COV2-2196 AAPYCSSISCNDGFDI 6 COV2-2901 ARSYDILTGYRDAFDI 7 COV2-2070 ARVGYSQGYYYYYMDV 8 COV2-2132 ARDFLRWHDL 9 COV2-2911 ARMSRGYNYAYTFDI 10 COV2-2098 VKGLFDWFPL 11 COV2-2108 AKGVDYGGKLAYFDS 12 COV2-2114 ARGRGYSNYGASYYMDV 13 COV2-2304 ARDPVWVDGELLSGGIPFDY 14 COV2-2078 ARVGVSGFKSGSNWYFDL 15 COV2-2299 ARDIDSGYDPTPVFDY 16 COV2-2351 ARRFYGPSSFDY 17 COV2-2318 ARGVVTYDY 18 COV2-2703 ARARGGYNWNFDY 19 COV2-2277 ARDVPTTVTAFTVFTY 20 COV2-2068 ARSYDILTGYRDAFDI 21 COV2-2504 ARVVVLGYGRPNNYYDGRNVWDY 22 COV2-2510 ARWGPDYGDYASNDY 23 COV2-2308 VKGLFDWFPL 24 COV2-2391 ARMRSGWPTHGRPDDF 25 COV2-2767 ARSYDILTGYRDAFDI 26 COV2-2113 ARDFLRWHDL 27 COV2-2290 ARMRSGWPTHGRPDDF 28 COV2-2130 TTAGSYYYDTVGPGLPEGKFDY 29 COV2-2050 ARVVVLGYGRPNNYYDGRNVWDY .. ... ... 355 COV2-2587 AHRLWFRDAFDI 356 COV2-2551 ASGPPYMATFSYYFDY 357 COV2-2481 ARGWFGELLKGTYWFDP 358 COV2-2029 ARPTAGAGGAFDI 359 COV2-2590 ARGRVGYVGSGSRGYYYYYDMDV 360 COV2-2408 ARVGGISPYYYYYYMDV 361 COV2-2565 ARGAASFDY 362 COV2-2641 AKSYNGNYYDAFDI 363 COV2-2449 ARASYNSNWSIGEYFRD 364 COV2-2619 ARVEGDWLLGGPYYHYYGMDV 365 COV2-2367 ARTSHYDSSGSYFEY 366 COV2-2343 ARVQRRRLDY 367 COV2-2270 AITYYYDSSGYWWDD 368 COV2-2187 ARGGATNFDY 369 COV2-2478 AKGIYYDIFMPLLD 370 COV2-2820 ARDQSQGAYILTGYRGYGMDV 371 COV2-2620 ARADTMVRGTYFEY 372 COV2-2171 ARLSGSSWDFDY 373 COV2-2583 ARGGIYYLVRGFIIGYYGMDV 374 COV2-2227 ARDQSQGAYILTGYRGYGMDV 375 COV2-2160 ARSTSGSYYYGMDV 376 COV2-2178 ARVGSSSWYFDY 377 COV2-2159 ARSTSGSYYYGMDV 378 COV2-2166 ARIGHFDSSGYYLDY 379 COV2-2224 AKDGSIAAADY 380 COV2-2214 ARIGHFDSSGYYLDY 381 COV2-2218 ARPYTGSYKSYMDV 382 COV2-2216 ARTSHYDSSGSYFEY 383 COV2-2175 ARLSGSSWDFDY 384 COV2-2183 ARADTMVRGTYFEY [385 rows x 2 columns] Name CDRH3 0 COV2-2997 ARGAIPPNSRAEIDY 1 COV2-3012 ARVLYDSSGFYNWFDP 2 COV2-2961 AAPYCSSISCNDGFDI 3 COV2-3025 AAPYCSSISCNDGFDI 4 COV2-2046 AKAHSTGHQYYYGMDV 5 COV2-2196 AAPYCSSISCNDGFDI 6 COV2-2901 ARSYDILTGYRDAFDI 7 COV2-2070 ARVGYSQGYYYYYMDV 8 COV2-2132 ARDFLRWHDL 9 COV2-2911 ARMSRGYNYAYTFDI 10 COV2-2098 VKGLFDWFPL 11 COV2-2108 AKGVDYGGKLAYFDS 12 COV2-2114 ARGRGYSNYGASYYMDV 13 COV2-2304 ARDPVWVDGELLSGGIPFDY 14 COV2-2078 ARVGVSGFKSGSNWYFDL 15 COV2-2299 ARDIDSGYDPTPVFDY 16 COV2-2351 ARRFYGPSSFDY 17 COV2-2318 ARGVVTYDY 18 COV2-2703 ARARGGYNWNFDY 19 COV2-2277 ARDVPTTVTAFTVFTY 20 COV2-2068 ARSYDILTGYRDAFDI 21 COV2-2504 ARVVVLGYGRPNNYYDGRNVWDY 22 COV2-2510 ARWGPDYGDYASNDY 23 COV2-2308 VKGLFDWFPL 24 COV2-2391 ARMRSGWPTHGRPDDF 25 COV2-2767 ARSYDILTGYRDAFDI 26 COV2-2113 ARDFLRWHDL 27 COV2-2290 ARMRSGWPTHGRPDDF 28 COV2-2130 TTAGSYYYDTVGPGLPEGKFDY 29 COV2-2050 ARVVVLGYGRPNNYYDGRNVWDY .. ... ... 355 COV2-2587 AHRLWFRDAFDI 356 COV2-2551 ASGPPYMATFSYYFDY 357 COV2-2481 ARGWFGELLKGTYWFDP 358 COV2-2029 ARPTAGAGGAFDI 359 COV2-2590 ARGRVGYVGSGSRGYYYYYDMDV 360 COV2-2408 ARVGGISPYYYYYYMDV 361 COV2-2565 ARGAASFDY 362 COV2-2641 AKSYNGNYYDAFDI 363 COV2-2449 ARASYNSNWSIGEYFRD 364 COV2-2619 ARVEGDWLLGGPYYHYYGMDV 365 COV2-2367 ARTSHYDSSGSYFEY 366 COV2-2343 ARVQRRRLDY 367 COV2-2270 AITYYYDSSGYWWDD 368 COV2-2187 ARGGATNFDY 369 COV2-2478 AKGIYYDIFMPLLD 370 COV2-2820 ARDQSQGAYILTGYRGYGMDV 371 COV2-2620 ARADTMVRGTYFEY 372 COV2-2171 ARLSGSSWDFDY 373 COV2-2583 ARGGIYYLVRGFIIGYYGMDV 374 COV2-2227 ARDQSQGAYILTGYRGYGMDV 375 COV2-2160 ARSTSGSYYYGMDV 376 COV2-2178 ARVGSSSWYFDY 377 COV2-2159 ARSTSGSYYYGMDV 378 COV2-2166 ARIGHFDSSGYYLDY 379 COV2-2224 AKDGSIAAADY 380 COV2-2214 ARIGHFDSSGYYLDY 381 COV2-2218 ARPYTGSYKSYMDV 382 COV2-2216 ARTSHYDSSGSYFEY 383 COV2-2175 ARLSGSSWDFDY 384 COV2-2183 ARADTMVRGTYFEY [385 rows x 2 columns] `; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } // The result can be accessed through the `m`-variable. m.forEach((match, groupIndex) => { console.log(`Found match, group ${groupIndex}: ${match}`); }); }

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 JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions