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
Processing...

Test String

Code Generator

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "(?<first><<<<<<< HEAD\\n.*?)(?<========)|(?<second>(?=>>>>>>>).*?\\n)"; final String string = "<<<<<<< HEAD\n" + "import { readdir } from \"fs\";\n" + "import { createServer } from \"../src/server.js\";\n" + "import Jasmine from 'jasmine';\n" + "import dotenv from 'dotenv';\n\n" + "const jasmine = new Jasmine();\n" + "=======\n" + "import { start } from \"../src/index.js\";\n\n" + "import dotenv from 'dotenv';\n" + "import { readdir } from \"fs\";\n" + "import Jasmine from 'jasmine';\n" + "import { resolve } from 'path';\n\n" + ">>>>>>> c80322f... Refactor codebase. Removed ml parts into separate project.\n" + "// jasmine.loadConfigFile(`tests/jasmine.json`);\n\n" + "const importTests = () => {\n" + " return new Promise((resolve, reject) => {\n" + " readdir(`./tests`, (err, files) => {\n" + " if (err) {\n" + " reject(err);\n" + " }\n" + " files = files.filter(file => { \n" + " return file.includes(`test.js`);\n" + " });\n" + " console.log(files);\n" + " files = files.map(file => { \n" + " const relativePath = `./${file}`;\n" + " return import(relativePath)\n" + " .catch(error => {\n" + " console.error(`** Error loading ` + relativePath + `: `);\n" + " console.error(error);\n" + " process.exit(1);\n" + " });\n" + " });\n\n" + " resolve(Promise.all(files));\n" + " });\n" + " });\n" + "};\n\n" + "const runTests = () => {\n" + "<<<<<<< HEAD\n" + " dotenv.config();\n\n" + " importTests().then(() => {\n" + " const server = createServer({\n" + " useAuth: false,\n" + " });\n\n" + " server.options.port = 4040;\n" + " process.env.GRAPHQL_ENDPOINT = `http://127.0.0.1:4040`;\n\n" + " server.start(() => {\n" + " console.log(`Test server is running on 127.0.0.1:${server.options.port}`);\n" + " jasmine.execute();\n" + " });\n" + "=======\n" + " const jasmine = new Jasmine();\n" + " const environment = process.env.NODE_ENV || `staging`;\n\n" + " dotenv.config({\n" + " path: resolve(`../src/config/${environment}/.env`),\n" + " });\n\n" + " importTests().then(async () => {\n" + " process.env.MONGODB_URIS = `mongodb+srv://f4a-shared-t95ry.gcp.mongodb.net/test`;\n" + " process.env.GRAPHQL_ENDPOINT = `http://127.0.0.1:4040`;\n" + " process.env.PORT = `4040`;\n" + " await start();\n" + " console.log(`Test server is running on 127.0.0.1:${server.port}`);\n" + " jasmine.execute();\n" + ">>>>>>> c80322f... Refactor codebase. Removed ml parts into separate project.\n" + " });\n" + "};\n" + "runTests();"; 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