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

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "\\b(?<=\\w)\\s{20}"; final String string = "Ateles_geoffroyi GATGAGTGTGGCAAGGCCCAAGCGGAAGTGCCG--GTTGCT\n" + "Ateles_hybridus GATGAGTGTGGCAAGGCCCAAGCGGAAGTGCCG--GTTGCT\n" + "Ateles_fusciceps GATGAGTGTGGCAAGGCCCAAGCGGAAGTGC??????????\n" + "Ateles_chamek GATGAGTGTGGCAAGGCCCA?????????????????????\n" + "Ateles_paniscus ?????????????????????????????????????????\n" + "Brachyteles_arachnoides GATGAGTGTGGCAAGGCCCAAGCGGAAGT????????????\n" + "Brachyteles_hypoxanthus GATGAGTGTGGCAAG??????????????????????????\n" + "Lagothrix_cana GATGAGTGTGGCAAGGCCCAAGCGGAAGTGCCG--GTTGCT\n" + "Lagothrix_lagotricha GATGAGTGTGGCAAGGCCCAAGCGGAAGTGCCG--GTTGCT\n" + "Alouatta_belzebul ?????????????????????????????????????????\n" + "Alouatta_caraya ?????????????????????????????????????????\n" + "Alouatta_sara GATGAATGTGGCAAGGCCCAAGCAGAAGTGCCG--GTTGCT\n" + "Alouatta_palliata GATGAATGTGGCAAGGCCCAAGCAGAAGTGCCG--GTTGCT\n" + "Callicebus_brunneus ?????????????????????????????????????????\n" + "Callicebus_moloch GATGAGTGTGGCAAGGCCCAAGCAGAAGTGCCG--G?????\n" + "Callicebus_cupreus GATGAGTGTGGCAAGGCCCAAGCAGAAGTGCCG--GTTGCT\n" + "Callicebus_caligatus GATGAGTGTGGCAAGGCCCAAGCAGAAGTGCCG--GTTGCT\n" + "Callicebus_donacophilus GATGAGTGTGGCAAGGCCCAAGCAGAAGTGCCG--GTTGCT\n" + "Callicebus_coimbrai GATGAGTGTGGCAAGGCCCAAGCGGAAGTGCCG--GTTGCT\n" + "Callicebus_personatus GATGAGTGTGGCAAGGCCCAAGCGGAA??????????????\n" + "Callicebus_nigrifrons GATGAGTGTGGCAAGGCCCAAGCGGAAGTGCCG--GTTGCT\n" + "Cacajao_melanocephalus GATGAGTGTGGCAAAGCCCA?????????????????????\n" + "Cacajao_calvus GATGAGTGTGGCAAGGCCCAAGCGGAAGTGCCG--GTTGCT\n" + "Chiropotes_israelita GATGAGTGTGGCAAGGCCCAAGCGGAAGTGCCG--GTTGCT\n" + "Chiropotes_satanas_chiro ?????????????????????????????????????????\n" + "Pithecia_irrorata GATGAGTGTGGCAAGGCCCAAGCGGAAGTGCCG--G?????\n" + "Pithecia_pithecia GATGAGTGTGGCAAGGCCCAAGCGGAAGTGCCG--GTTGCT\n" + "Tarsius_bancanus ?????????????????????????????????????????\n" + "Tarsius_syrichta ?????????????????????????????????????????\n" + "Lepilemur_ankaranensis AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Lepilemur_septentrionali AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Lepilemur_dorsalis AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Lepilemur_ruficaudatus AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Lepilemur_jamesi AACGAGTGTGGCAAGGCCCAGG???????????????????\n" + "Microcebus_murinus_subsp AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Microcebus_murinus_subsp ?????????????????????????????????????????\n" + "Mirza_zaza AACGAGTGTGGCAAGGCCCAGGCAGAAGTTCCG--GTTGCT\n" + "Cheirogaleus_medius ?????????????????????????????????????????\n" + "Propithecus_verreauxi_co ?????????????????????????????????????????\n" + "Propithecus_verreauxi AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Propithecus_tattersalli AACGAGTGTGGCAAGGCCCAGGCTGAAGTTCCG--GTTGCT\n" + "Propithecus_diadema AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Propithecus_edwardsi AACGAGTGTGGCAAGGCCCAGGCG?????????????????\n" + "Avahi_laniger AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Eulemur_rufus AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Eulemur_collaris AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Eulemur_fulvus AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Eulemur_albifrons AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Eulemur_sanfordi AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Eulemur_mongoz AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Eulemur_macaco AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Eulemur_macaco_flavifron AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Eulemur_coronatus AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Eulemur_rubriventer AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Hapalemur_occidentalis AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Hapalemur_griseus AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Lemur_catta AACGAGTGTGGCAAGGCCCAGGCGGAAGTTCCG--GTTGCT\n" + "Varecia_variegata_varieg AACGAGTGTGGCAAGGCCCAGGCAGAAGTTCCG--GTTGCT\n" + "Varecia_variegata_rubra AACGAGTGTGGCAAGGCCCAGGCAGAAGTTCCG--GTTGCT\n" + "Daubentonia_madagascarie ?????????????????????????????????????????\n" + "Nycticebus_bengalensis AACGAGTGTGGCAAGGCCCAGGCAGAAGTTCCG--GTTGCT\n" + "Nycticebus_coucang AACGAGTGTGGCAAGGCCCAGGCAGAAGTTCCG--GTTGCT\n" + "Nycticebus_pygmaeus AACGAGTATGGCAAGGCCCAGGCAGAAGTTCCG--GTTGCT\n" + "Loris_tardigradus AACGAGTGTGGCAAGGCCCAGGCAGAAGTTCCG--GTTGCT\n" + "Arctocebus_calabarensis AACGAGTGTGGCAAGGCCCAGGCAGAAGTTCCG--GTTGCT\n" + "Perodicticus_potto AACGAGTGTGGCAAGGCCCAGGCAGAAGTTCCG--GTTGCT\n" + "Otolemur_garnetti AACGAGTGTGGCAAGGCCCAGGCAGAAGTTCCG--GTTGCT\n" + "Otolemur_crassicaudatus AACGAGTGTGGCAAGGCCCAGGCAGAAGTTCCG--GTTGCT\n" + "Galago_moholi ?????????????????????????????????????????\n" + "Galago_senegalensis ?????????????????????????????????????????\n" + "Galago_thomasi AACGAGTGTGGCAAGGCCCAGGCG?????????????????\n" + "Galeopterus_variegatus GATGAGTGTGGCAAGGCCCAAGCAGAAGTTCCG--G?????\n" + "Cynocephalus_volans GATGAGTGTGGCAAGGCCCAAGCAGAAGTCCCG--GTTGCT\n" + "Tupaia_glis ?????????????????????????????????????????\n" + "Tupaia_minor ?????????????????????????????????????????\n" + "rabbit_rabbit_rabbit ?????????????????????????????????????????\n"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); while (matcher.find()) { System.out.println("Full match: " + matcher.group(0)); for (int i = 1; i <= matcher.groupCount(); i++) { System.out.println("Group " + i + ": " + matcher.group(i)); } } } }

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 Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html