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

~
~
sg

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 = "(.*?) => (\\d+)(?: *\\R|$)"; final String string = "0 => 129367\n" + "1 => 998023\n" + "2 => 971513\n" + "3 => 365366\n" + "4 => 247647\n" + "5 => 131747\n" + "6 => 86151\n" + "7 => 898342\n" + "8 => 591121\n" + "9 => 828966\n" + "a => 185363\n" + "b => 420016\n" + "c => 472728\n" + "d => 185475\n" + "e => 669058\n" + "f => 472944\n" + "g => 932915\n" + "h => 109171\n" + "i => 940561\n" + "j => 483250\n" + "k => 240419\n" + "l => 158223\n" + "m => 494635\n" + "n => 205943\n" + "o => 19961\n" + "p => 989725\n" + "q => 125777\n" + "r => 195604\n" + "s => 818227\n" + "t => 83779\n" + "u => 990539\n" + "v => 639213\n" + "w => 669743\n" + "x => 546240\n" + "y => 950155\n" + "z => 631005\n" + "A => 126161\n" + "B => 403898\n" + "C => 323151\n" + "D => 536228\n" + "E => 653494\n" + "F => 810236\n" + "G => 808261\n" + "H => 900915\n" + "I => 60916\n" + "J => 417663\n" + "K => 371534\n" + "L => 384244\n" + "M => 900004\n" + "N => 300998\n" + "O => 346538\n" + "P => 5044\n" + "Q => 558707\n" + "R => 404479\n" + "S => 183163\n" + "T => 505254\n" + "U => 497969\n" + "V => 197795\n" + "W => 953877\n" + "X => 394637\n" + "Y => 760236\n" + "Z => 211436\n" + "! => 601326\n" + "\" => 15745\n" + "# => 428427\n" + "$ => 602548\n" + "% => 938126\n" + "& => 159405\n" + "' => 528113\n" + "( => 8021\n" + ") => 910309\n" + "* => 747795\n" + "+ => 232242\n" + ", => 731593\n" + "- => 808534\n" + ". => 429705\n" + "/ => 916854\n" + ": => 241543\n" + "; => 755104\n" + "< => 314595\n" + "= => 398161\n" + "> => 606925\n" + "? => 804662\n" + "@ => 713498\n" + "[ => 431477\n" + "\\ => 80381\n" + "] => 36645\n" + "^ => 156790\n" + "_ => 34787\n" + "` => 107682\n" + "{ => 283663\n" + "| => 650856\n" + "} => 91921\n" + "~ => 752056\n" + " => 494223\n" + " => 521932\n\n" + " => 816279\n" + " => 301703\n" + " => 17163\n" + " => 867641\n" + "ą => 817209\n" + "ś => 594615\n" + "ż => 570356\n" + "ź => 913303\n" + "ł => 752084\n" + "ó => 838178\n" + "ę => 693877\n" + "ń => 564418\n" + "ć => 30975\n" + "Ż => 707466"; final Pattern pattern = Pattern.compile(regex, Pattern.DOTALL); 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