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

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "\\.populate_tasks\\[(arc|buck|build|hg|phabricator|source_control),"; final String string = "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[arc,diff]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[arc,fix]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[arc,focus]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[arc,lint]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[arc,pull]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[arc,refocus]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[buck,build]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[buck,install]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[buck,project]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[buck,run]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[buck,test]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[build,arc_rebuild]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[build,buck_build]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[build,entschema]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[build,fbios_noextensions]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[build,instagram_ios_noextensions]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[build,messenger_ios_noextensions]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[build,multifeed]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[build,unicorn]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[build,wakizashi]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[build,wakizashi_s2p]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[devserver,arc_fix]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[devserver,fixmyserver]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[devserver,flow_oom]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[devserver,hack_oom]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[devserver,hhserver_oom]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[hack,hh_healthy_minutes]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[hg,amend]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[hg,bookmarks]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[hg,branch]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[hg,commit]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[hg,diff]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[hg,log]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[hg,pull]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[hg,rebase]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[hg,smartlog]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[hg,status]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[hg,update]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[ide,flow_check]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[ide,flow_init]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[ide,hh_full_check]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[ide,hh_lazy_check]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[ide,hh_server_init]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[ide,intellij_file_to_intellisense]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[ide,intellij_project_to_intellisense]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[land,clean_lands]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[land,landcastle]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[phabricator,diffusion_pageload]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[phabricator,gql_client_duration]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[phabricator,gql_mutation_duration]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[phabricator,jf_submit_set_dependencies]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[phabricator,jf_submit_set_diffproperty]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[phabricator,jf_submit_total_elapsed]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[phabricator,jf_submit_update_diff]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[phabricator,jf_submit_update_revision]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[presto,adhoc_queue]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[source_control,hg]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[source_control,jellyfish]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[test,local_www]\n" + "── infrastructure.devspeed.error_rates.devspeed_raw_cost_events.populate_tasks[test,mobilelab]"; 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