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 = "\\[([^\\]]+)]\"?$"; final String string = "NO MATCHES:\n\n" + " [q:Sacks and Snow: The Snow Child's Name] has run out of time. It asks to see you.\n\n" + " \"My sleep is riddled with dreams, [q:Addressed As]. Dreams of bells and candles!\"\n\n" + " The pirates must learn that [q:Pigmote Isle: Mastery] will fight back.\n\n" + " [CHANGE_TERRAIN],EmpireofHands/airbase_half,EmpireofHands/airbase_burnt\n\n" + " <b>MAYBE'S DAUGHTER</b>: Hello, Auntie.\\r\\n<br/>\\r\\n<b>PARABOLAN PANTHER<b/>: [Silence.]\\r\\n<br/>\\r\\n<b>MAYBE'S DAUGHTER</b>: Fair point. Let's keep it to ourselves for now.\\r\\n\n\n" + " O[xxxxx] THRR [xxxxx] N KUTHE TH[xxxxxx].\n\n\n" + "SHOULD MATCH:\n\n" + " \"[q:Addressed As]. I know the way. Let me show you.\"\\n[The Exile is a First Officer.]\n\n" + "(just the last part!)\n\n" + " \"Herein are recorded certain details of a Voyage through [xxxxx] in the company of [xxxxxx], on [xxxxxx]....\" [Use this to increase your Pages]\n\n\n" + "(how? it ends with quotes!)\n\n" + " \"P drowns in PELIGIN, the colour of the deepest zee. [Someone has scrawled in the margin: BEYOND THE GATE THERE IS A SEA MORE SUNLESS]\"\n\n" + "(trailing spaces)\n\n" + " Decide later. [If you just want to get out to zee immediately, choose this. Opportunities to revisit your past will arrive later.]\n\n" + " Really it's just him you want to understand. [This will certainly get you kicked off the island.]\n\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