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 = "(?<=<!-- Template Nav Start -->[\\n])([\\n\\s\\S]*?)(?=[\\s\\n]*?<!-- Template Nav End -->)"; final String string = "<!DOCTYPE html>\n" + "<html lang=\"en\">\n\n" + " <head>\n" + " <meta charset=\"UTF-8\">\n" + " <meta http-equiv=\"X-UA-Compatible\" content=\"IE=edge\">\n" + " <meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">\n" + " <meta property=\"og:site_name\" content=\"WD Proposal\">\n" + " <meta property=\"og:title\" content=\"Your new outdoor living space.\">\n" + " <meta property=\"og:image\" content=\"https://www.WhitmerDecks.com/Proposal/eProposal/img/wdLogoName.png\">\n" + " <meta property=\"og:description\" content=\"Here you can view the proposal from Whitmer Decks, LLC\">\n" + " </meta>\n\n" + " <!-- General scripts & styles -->\n" + " <link rel=\"stylesheet\" href=\"css/styles.css\">\n" + " <link rel=\"stylesheet\" href=\"css/cwBootstrap.css\">\n" + " <script src=\"js/cwBootstrap.js\" defer></script>\n\n" + " <!-- Google Fonts -->\n" + " <link href=\"https://fonts.googleapis.com/css?family=Roboto:300,400,500,700&display=swap\" rel=\"stylesheet\">\n\n" + " <!-- Page title and end of general head -->\n" + " <title>WD Proposal</title>\n\n" + " <!-- Page specific scripts and styles -->\n" + " <script src=\"js/about.js\" defer></script>\n" + " </head>\n\n" + " <body>\n\n" + " <!-- Template Nav Start -->\n" + " <nav>\n" + " <ul>\n" + " <li><a href=\"index.html\">Home</a></li>\n" + " <li><a href=\"about.html\">About</a></li>\n" + " <li>Item X</li>\n" + " <li>Item Y</li>\n" + " </ul>\n" + " </nav>\n" + " <!-- Template Nav End -->\n\n" + " <p>\n" + " The about page\n" + " </p>\n\n" + " </body>\n\n" + "</html>"; 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