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"
"
gsm

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+) 0 obj[^>]+/Page$"; final String string = "%PDF-1.3\n" + "%¦¦¦¦\n\n" + "1 0 obj\n" + "<<\n" + "/Type /Catalog /AcroForm << /Fields [12 0 R 13 0 R] /NeedAppearances false /SigFlags 3 /Version /1.7 /Pages 3 0 R /Names << >> /ViewerPreferences << /Direction /L2R >> /PageLayout /SinglePage /PageMode /UseNone /OpenAction [0 0 R /FitH null] /DR << /Font << /F1 14 0 R >> >> /DA (/F1 0 Tf 0 g) /Q 0 >> /Perms << /DocMDP 11 0 R >>\n" + "/Outlines 2 0 R\n" + "/Pages 3 0 R\n" + ">>\n" + "endobj\n\n" + "2 0 obj\n" + "<<\n" + "/Type /Outlines\n" + "/Count 0\n" + ">>\n" + "endobj\n\n" + "3 0 obj\n" + "<<\n" + "/Type /Pages\n" + "/Count 2\n" + "/Kids [ 4 0 R 6 0 R ]\n" + ">>\n" + "endobj\n\n" + "4 0 obj\n" + "<<\n" + "/Type /Page\n" + "/Parent 3 0 R\n" + "/Resources <<\n" + "/Font <<\n" + "/F1 9 0 R\n" + ">>\n" + "/ProcSet 8 0 R\n" + ">>\n" + "/MediaBox [0 0 612.0000 792.0000]\n" + "/Contents 5 0 R\n" + ">>\n" + "endobj\n\n" + "5 0 obj\n" + "<< /Length 1074 >>\n" + "stream\n" + "2 J\n" + "BT\n" + "0 0 0 rg\n" + "/F1 0027 Tf\n" + "57.3750 722.2800 Td\n" + "( A Simple PDF File ) Tj\n" + "ET\n" + "BT\n" + "/F1 0010 Tf"; final Pattern pattern = Pattern.compile(regex, Pattern.DOTALL | 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