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

/
/
gmi

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 = "\\{#include\\s*([\\w.]+)\\s*\\}"; final String string = "{#include header.html}\n" + " <header class=\"bg-gradient-to-r from-purple-700 to-indigo-800 shadow-lg w-full\">\n" + " <div class=\"max-w mx-auto px-4 sm:px-6 lg:px-8 py-6\">\n" + " <div class=\"flex flex-col items-center justify-between md:flex-row\">\n" + " <a href=\"/\">\n" + " <h1 class=\"mb-4 text-2xl font-bold text-white md:mb-0 md:text-3xl\">Header</h1>\n" + " </a>\n" + " <nav class=\"flex space-x-4\">\n" + " <a href=\"/\">\n" + " <a href=\"#\" class=\"text-white transition duration-150 ease-in-out hover:text-purple-200\">Home</a>\n" + " </a>\n" + " <a href=\"#\" class=\"text-white transition duration-150 ease-in-out hover:text-purple-200\">About</a>\n" + " <a href=\"#\" class=\"text-white transition duration-150 ease-in-out hover:text-purple-200\">Contact</a>\n" + " </nav>\n" + " </div>\n" + " </div>\n" + " </header>\n\n" + " <div class=\"flex flex-grow\">\n" + " <aside class=\"w-72 bg-gray-100 scrollable-column\">\n" + " <div class=\"p-6\">\n" + " <h2 class=\"mb-4 text-xl font-semibold text-gray-800\">Directories</h2>\n" + " {#each item in dirs}\n" + " <div class=\"mb-3\">\n" + " <a href=\"{item.link}\"\n" + " class=\"font-medium text-indigo-600 transition duration-150 ease-in-out hover:text-indigo-800\">{item.name}</a>\n" + " </div>\n" + " {/each}\n" + " </div>\n" + " </aside>\n\n" + " <main class=\"flex-grow bg-white scrollable-column\">\n" + " <div class=\"p-6 md:p-8\">\n" + " {#each item in files}\n" + " <div class=\"space-y-4\">\n" + " <div class=\"flex flex-col sm:flex-row border-b-2 border-gray-200 pb-4\">\n" + " <div class=\"w-full sm:w-[150px] h-[150px] border-2 border-black flex items-center justify-center overflow-hidden mb-4 sm:mb-0 flex-shrink-0\">\n" + " <a href=\"{item.link}\">\n" + " <img src=\"{item.image}\" alt=\"thumbnail\" class=\"w-full h-full object-cover\">\n" + " </a>\n" + " </div>\n" + " <div class=\"flex-grow pt-2 sm:pl-4\">\n" + " <h3 class=\"mb-2 text-xl font-semibold\">\n" + " <a href=\"{item.link}\"\n" + " class=\"text-indigo-600 transition duration-150 ease-in-out hover:text-indigo-800\">{item.name}</a>\n" + " </h3>\n" + " <p class=\"text-black text-sm -mt-2 mb-2\">{item.date}</p>\n" + " <p class=\"text-gray-600 text-lg\">{item.summery}</p>\n" + " </div>\n" + " </div>\n" + " </div>\n" + " {/each}\n" + " </div>\n" + " </main>\n" + " </div>\n\n" + " <footer class=\"bg-gray-800 text-white\">\n" + " <div class=\"container mx-auto px-4 py-8\">\n" + " <div class=\"flex flex-col items-center justify-between md:flex-row\">\n" + " <div class=\"mb-4 text-2xl font-semibold md:mb-0\">Footer</div>\n" + " <div class=\"flex space-x-4\">\n" + " <a href=\"#\" class=\"transition duration-150 ease-in-out hover:text-purple-300\">Privacy</a>\n" + " <a href=\"#\" class=\"transition duration-150 ease-in-out hover:text-purple-300\">Terms</a>\n" + " <a href=\"#\" class=\"transition duration-150 ease-in-out hover:text-purple-300\">Contact</a>\n" + " </div>\n" + " </div>\n" + " </div>\n" + " </footer>\n" + "{#include footer.html}\n"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE | Pattern.CASE_INSENSITIVE); 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