code-snippets.ts

export type Chapter = {
  title: string;
  code: string | null;
};

export type Language = {
  name: string;
  chapters: Chapter[];
};

export const codeSnippets: Record<string, Language> = {
  typing: {
    name: "Typing Skills",
    chapters: [
      { title: "Easy 1", code: `The sun is shining and the birds are singing. It's a beautiful day to go for a walk in the park. Many people enjoy the simple pleasures of life.` },
      { title: "Easy 2", code: `My friend and I are going to the movies tonight. We are excited to see the new film. Popcorn is a must-have snack for any movie.` },
      { title: "Easy 3", code: `Cooking can be a fun and relaxing hobby. I like to try new recipes on the weekend. My favorite dish to make is pasta with fresh tomatoes.` },
      { title: "Easy 4", code: `Reading a good book is a great way to unwind. I have a collection of classic novels. The library is a wonderful place to discover new authors.` },
      { title: "Easy 5", code: `Music can lift your spirits and change your mood. I enjoy listening to a wide variety of genres. A catchy song can stay in your head for days.` },
      { title: "Easy 6", code: `Learning a new skill takes time and patience. Practice is the key to improvement. It is rewarding to see your progress over time.` },
      { title: "Easy 7", code: `Traveling allows you to experience different cultures. I dream of visiting far-off lands. Every journey begins with a single step.` },
      { title: "Easy 8", code: `Keeping a journal can help you organize your thoughts. Writing down your ideas is a good habit. It's interesting to look back at old entries.` },
      { title: "Easy 9", code: `Spending time with family and friends is important. Strong relationships are built on trust and love. Laughter is the best medicine for the soul.` },
      { title: "Easy 10", code: `A healthy diet and regular exercise are vital for well-being. Eating fresh fruits and vegetables is good for you. A morning run can energize your day.` },
      { title: "Moderate 1", code: `The quick brown fox jumps over the lazy dog. This sentence contains every letter of the alphabet. It's a classic pangram used for typing practice.` },
      { title: "Moderate 2", code: `Technology has revolutionized the way we live and work, offering both convenience and new challenges. We must adapt to keep up with the pace of innovation.` },
      { title: "Moderate 3", code: `Juggling multiple tasks requires strong organizational skills. Prioritizing your work and managing your time effectively are crucial for success.` },
      { title: "Moderate 4", code: `The sphinx of black quartz, judge my vow. This pangram is more complex and poetic. It tests your ability to type less common letter combinations.` },
      { title: "Moderate 5", code: `Climate change is a significant global issue that requires immediate attention. International cooperation is essential to find sustainable solutions.` },
      { title: "Moderate 6", code: `The history of the ancient world is filled with fascinating stories of empires, myths, and legends. Exploring these tales can be quite enlightening.` },
      { title: "Moderate 7", code: `Creativity is the ability to generate or recognize ideas, alternatives, or possibilities that may be useful in solving problems, communicating with others.` },
      { title: "Moderate 8", code: `Pack my box with five dozen liquor jugs. This is another popular pangram. It is short but effective for practicing all the letters.` },
      { title: "Moderate 9", code: `The pursuit of knowledge is a lifelong journey. Every day presents an opportunity to learn something new and expand your understanding of the world.` },
      { title: "Moderate 10", code: `Problem-solving involves defining a problem, determining the cause, identifying, prioritizing, and selecting alternatives for a solution.` },
      { title: "Hard 1", code: `~ \` ! @ # $ % ^ & * ( ) _ - + = { } [ ] | \\ : ; " ' < > , . ? /` },
      { title: "Hard 2", code: `The function's signature is func(arg1, arg2) -> { return arg1 + arg2; }. Pay attention to the syntax: parentheses(), curly braces{}, and arrows->.` },
      { title: "Hard 3", code: `My password is "p@$$w0rd_!@#". It's a mix of special characters, numbers, and letters for security. Remember to use strong, unique passwords.` },
      { title: "Hard 4", code: `The file path is C:\\Users\\Default\\Documents. Notice the backslashes (\\) and colons (:). This is a common format in Windows.` },
      { title: "Hard 5", code: `The JSON object is {"key": "value", "number": 123}. It uses quotes, colons, and commas to structure data. This is a popular data interchange format.` },
      { title: "Hard 6", code: `SQL queries like SELECT * FROM users WHERE id = 1; often contain special characters. Semicolons (;), asterisks (*), and equal signs (=) are common.` },
      { title: "Hard 7", code: `Regular expressions such as /^[a-z0-9_-]{3,16}$/ are powerful but complex. They use characters like ^, $, -, and {}.` },
      { title: "Hard 8", code: `HTML tags like <div class="container"> require angle brackets and quotes. Attributes are assigned with an equals sign.` },
      { title: "Hard 9", code: `You can reach me at 'user.name+alias@example.com'. Email addresses can contain periods, plus signs, and the at symbol (@).` },
      { title: "Hard 10", code: `The calculation is ( ( 5 + 3 ) * 2 ) / 4 = 4. Parentheses are used to control the order of operations in mathematics.` }
    ]
  },
  javascript: {
    name: "JavaScript",
    chapters: [
      { title: "Chapter 1: Variables", code: `const name = "CodeType";\nlet version = 1.0;\nvar isAwesome = true;\n\nfunction greet(user) {\n  console.log("Hello, " + user);\n}\n\ngreet(name);` },
      { title: "Chapter 2: Functions", code: `function add(a, b) {\n  return a + b;\n}\n\nconst multiply = (x, y) => {\n  return x * y;\n};\n\nconst result = add(5, 10);\nconsole.log(multiply(result, 2));` },
      { title: "Chapter 3: Arrays", code: `const numbers = [1, 2, 3, 4, 5];\nconst squares = numbers.map(n => n * n);\n\nconst evenSquares = squares.filter(sq => {\n  return sq % 2 === 0;\n});\n\nconsole.log(evenSquares);` },
      { title: "Chapter 4: Objects", code: `const person = {\n  firstName: "John",\n  lastName: "Doe",\n  age: 30,\n  fullName: function() {\n    return this.firstName + " " + this.lastName;\n  }\n};\n\nconsole.log(person.fullName());` },
      { title: "Chapter 5: Conditionals", code: `let temperature = 25;\n\nif (temperature > 30) {\n  console.log("It's a hot day!");\n} else if (temperature > 20) {\n  console.log("It's a pleasant day.");\n} else {\n  console.log("It's a bit chilly.");\n}` },
      { title: "Chapter 6: Loops", code: `for (let i = 0; i < 5; i++) {\n  console.log("Iteration: " + i);\n}\n\nconst colors = ['red', 'green', 'blue'];\nfor (const color of colors) {\n  console.log(color);\n}` },
      { title: "Chapter 7: DOM Manipulation", code: `document.addEventListener('DOMContentLoaded', () => {\n  const container = document.getElementById('container');\n  const p = document.createElement('p');\n  p.textContent = 'This was added by JavaScript!';\n  container.appendChild(p);\n});` },
      { title: "Chapter 8: Events", code: `const button = document.querySelector('#myButton');\n\nbutton.addEventListener('click', () => {\n  alert('Button was clicked!');\n});` },
      { title: "Chapter 9: Async/Await", code: `async function fetchData() {\n  try {\n    const response = await fetch('https://api.example.com/data');\n    const data = await response.json();\n    console.log(data);\n  } catch (error) {\n    console.error('Fetching data failed:', error);\n  }\n}` },
      { title: "Chapter 10: Promises", code: `const myPromise = new Promise((resolve, reject) => {\n  setTimeout(() => {\n    resolve("Success!");\n  }, 2000);\n});\n\nmyPromise.then(message => {\n  console.log(message);\n});` },
      { title: "Chapter 11: Classes", code: `class Animal {\n  constructor(name) {\n    this.name = name;\n  }\n\n  speak() {\n    console.log(this.name + ' makes a sound.');\n  }\n}\n\nconst dog = new Animal('Dog');\ndog.speak();` },
      { title: "Chapter 12: Modules", code: `// utils.js\nexport const PI = 3.14159;\nexport function double(n) { return n * 2; }\n\n// main.js\nimport { PI, double } from './utils.js';\nconsole.log(double(PI));` },
      { title: "Chapter 13: Destructuring", code: `const user = { id: 1, name: 'Satoshi' };\nconst { id, name } = user;\n\nconst numbers = [10, 20, 30, 40];\nconst [first, second] = numbers;` },
      { title: "Chapter 14: Spread & Rest", code: `const arr1 = [1, 2, 3];\nconst arr2 = [...arr1, 4, 5];\n\nfunction sum(...args) {\n  return args.reduce((acc, val) => acc + val, 0);\n}\nconsole.log(sum(1, 2, 3, 4));` },
      { title: "Chapter 15: Template Literals", code: `const framework = 'React';\nconst library = 'Next.js';\n\nconst sentence = \`We are using \${framework} with \${library}.\`;\nconsole.log(sentence);` },
      { title: "Chapter 16: Array Reduce", code: `const items = [ { price: 10 }, { price: 20 }, { price: 5 } ];\nconst total = items.reduce((sum, item) => sum + item.price, 0);\nconsole.log('Total price:', total);` },
      { title: "Chapter 17: Closures", code: `function createCounter() {\n  let count = 0;\n  return function() {\n    count++;\n    return count;\n  };\n}\n\nconst counter = createCounter();\nconsole.log(counter());` },
      { title: "Chapter 18: Prototypal Inheritance", code: `function Person(name) {\n  this.name = name;\n}\n\nPerson.prototype.greet = function() {\n  console.log('Hello, ' + this.name);\n};\n\nconst alice = new Person('Alice');\nalice.greet();` },
      { title: "Chapter 19: Fetch API", code: `fetch('https://jsonplaceholder.typicode.com/todos/1')\n  .then(response => response.json())\n  .then(json => console.log(json))\n  .catch(error => console.error('Error:', error));` },
      { title: "Chapter 20: Local Storage", code: `localStorage.setItem('username', 'test-user');\nconst username = localStorage.getItem('username');\n\nif (username) {\n  console.log('Welcome back, ' + username);\n}` },
      { title: "Chapter 21: Error Handling", code: `try {\n  let result = riskyOperation();\n  console.log(result);\n} catch (error) {\n  console.error('An error occurred:', error.message);\n} finally {\n  console.log('Cleanup code runs here.');\n}` },
      { title: "Chapter 22: Regular Expressions", code: `const text = 'The rain in Spain stays mainly in the plain.';\nconst regex = /ain/g;\nconst matches = text.match(regex);\nconsole.log(matches);` },
      { title: "Chapter 23: Set", code: `const letters = new Set(['a', 'b', 'c', 'a']);\nletters.add('d');\n\nfor (const letter of letters) {\n  console.log(letter);\n}` },
      { title: "Chapter 24: Map", code: `const userRoles = new Map();\nuserRoles.set('admin', 'Full access');\nuserRoles.set('editor', 'Can edit content');\n\nconsole.log(userRoles.get('admin'));` },
      { title: "Chapter 25: JSON", code: `const book = { title: '1984', author: 'George Orwell' };\nconst jsonString = JSON.stringify(book);\nconst bookObject = JSON.parse(jsonString);\nconsole.log(bookObject.title);` },
      { title: "Chapter 26: Web Workers", code: `// worker.js\nself.onmessage = function(e) {\n  const result = e.data * 2;\n  self.postMessage(result);\n}\n\n// main.js\nconst myWorker = new Worker('worker.js');` },
      { title: "Chapter 27: Generators", code: `function* numberGenerator() {\n  yield 1;\n  yield 2;\n  yield 3;\n}\n\nconst gen = numberGenerator();\nconsole.log(gen.next().value);` },
      { title: "Chapter 28: Symbols", code: `const idSymbol = Symbol('id');\nconst userObject = {\n  name: 'developer',\n  [idSymbol]: 123\n};\n\nconsole.log(userObject[idSymbol]);` },
      { title: "Chapter 29: Proxy", code: `const target = { message: 'hello' };\nconst handler = {\n  get: function(target, prop) {\n    return prop in target ? target[prop] : 'default';\n  }\n};\n\nconst proxy = new Proxy(target, handler);` },
      { title: "Chapter 30: Internationalization API", code: `const number = 123456.789;\n\nconsole.log(new Intl.NumberFormat('de-DE').format(number));\n\nconst date = new Date();\nconsole.log(new Intl.DateTimeFormat('en-GB').format(date));` }
    ],
  },
  python: {
    name: "Python",
    chapters: [
      { title: "Chapter 1: Hello World", code: `def main():\n    name = "Python"\n    print(f"Hello, {name}!")\n\nif __name__ == "__main__":\n    main()` },
      { title: "Chapter 2: Lists", code: `numbers = [1, 2, 3, 4, 5]\nsquared = [num**2 for num in numbers]\n\nfor s in squared:\n    if s > 10:\n        print(s)` },
      { title: "Chapter 3: Dictionaries", code: `user = {\n    "name": "Alice",\n    "age": 25,\n    "is_active": True\n}\n\nprint(f"{user['name']} is {user['age']} years old.")` },
      { title: "Chapter 4: Classes and Objects", code: `class Dog:\n    def __init__(self, name):\n        self.name = name\n\n    def bark(self):\n        return f"{self.name} says woof!"\n\nmydog = Dog("Rex")\nprint(mydog.bark())` },
      { title: "Chapter 5: File I/O", code: `with open("example.txt", "w") as f:\n    f.write("Hello, file world!\\n")\n\nwith open("example.txt", "r") as f:\n    content = f.read()\n    print(content)` },
      { title: "Chapter 6: Modules", code: `import math\n\nprint(f"The value of pi is {math.pi}")\n\nradius = 5\narea = math.pi * (radius ** 2)\nprint(f"Area of circle: {area}")` },
      { title: "Chapter 7: Inheritance", code: `class Animal:\n    def speak(self):\n        raise NotImplementedError\n\nclass Cat(Animal):\n    def speak(self):\n        return "Meow"\n\nmy_cat = Cat()\nprint(my_cat.speak())` },
      { title: "Chapter 8: Exception Handling", code: `try:\n    result = 10 / 0\nexcept ZeroDivisionError as e:\n    print(f"Error: {e}")\nfinally:\n    print("Execution complete.")` },
      { title: "Chapter 9: Tuples and Sets", code: `my_tuple = (1, 'apple', 3.14)\nmy_set = {1, 2, 3, 2, 1}\n\nprint(my_tuple[1])\nprint(my_set)` },
      { title: "Chapter 10: Lambdas", code: `multiply = lambda x, y: x * y\nprint(multiply(5, 4))\n\npoints = [(1, 2), (4, 1), (3, 5)]\npoints.sort(key=lambda p: p[1])\nprint(points)` },
      { title: "Chapter 11: Decorators", code: `def my_decorator(func):\n    def wrapper():\n        print("Something is happening before.")\n        func()\n        print("Something is happening after.")\n    return wrapper\n\n@my_decorator\ndef say_whee():\n    print("Whee!")` },
      { title: "Chapter 12: Generators", code: `def countdown(n):\n    while n > 0:\n        yield n\n        n -= 1\n\nfor i in countdown(5):\n    print(i)` },
      { title: "Chapter 13: Regular Expressions", code: `import re\n\ntext = "The quick brown fox jumps over the lazy dog."\nmatch = re.search(r"brown (\\w+)", text)\nif match:\n    print("Found:", match.group(1))` },
      { title: "Chapter 14: Working with JSON", code: `import json\n\ndata = {"name": "test", "value": 42}\njson_string = json.dumps(data)\nparsed_data = json.loads(json_string)` },
      { title: "Chapter 15: Datetime Module", code: `from datetime import datetime, timedelta\n\nnow = datetime.now()\nprint("Current time:", now)\nyesterday = now - timedelta(days=1)\nprint("Yesterday:", yesterday)` },
      { title: "Chapter 16: Virtual Environments", code: `python3 -m venv myenv\nsource myenv/bin/activate\n\npip install requests\ndeactivate` },
      { title: "Chapter 17: Concurrency with Threads", code: `import threading\n\ndef worker(num):\n    print(f"Worker: {num}")\n\nthreads = []\nfor i in range(5):\n    t = threading.Thread(target=worker, args=(i,))\n    threads.append(t)\n    t.start()` },
      { title: "Chapter 18: Asyncio", code: `import asyncio\n\nasync def main():\n    print("Hello")\n    await asyncio.sleep(1)\n    print("...world!")\n\nasyncio.run(main())` },
      { title: "Chapter 19: Context Managers", code: `class ManagedFile:\n    def __init__(self, filename):\n        self.filename = filename\n\n    def __enter__(self):\n        self.file = open(self.filename, 'w')\n        return self.file\n\n    def __exit__(self, *args):\n        if self.file:\n            self.file.close()` },
      { title: "Chapter 20: Argparse for CLI", code: `import argparse\n\nparser = argparse.ArgumentParser()\nparser.add_argument("echo", help="echo the string")\nargs = parser.parse_args()\nprint(args.echo)` },
      { title: "Chapter 21: Unit Testing", code: `import unittest\n\ndef add(a, b):\n    return a + b\n\nclass TestAdd(unittest.TestCase):\n    def test_add(self):\n        self.assertEqual(add(2, 3), 5)` },
      { title: "Chapter 22: Data Classes", code: `from dataclasses import dataclass\n\n@dataclass\nclass Point:\n    x: float\n    y: float\n\np = Point(1.0, 2.5)` },
      { title: "Chapter 23: Type Hinting", code: `def greeting(name: str) -> str:\n    return "Hello " + name\n\npi: float = 3.14159` },
      { title: "Chapter 24: Itertools", code: `import itertools\n\nfor i in itertools.count(10, 2):\n    if i > 20:\n        break\n    print(i)` },
      { title: "Chapter 25: Collections Module", code: `from collections import Counter\n\ncolors = ['red', 'blue', 'red', 'green', 'blue', 'blue']\ncolor_counts = Counter(colors)\nprint(color_counts)` },
      { title: "Chapter 26: Walrus Operator", code: `while (line := input("Enter text: ")) != "quit":\n    print(f"You entered: {line}")` },
      { title: "Chapter 27: F-strings Advanced", code: `import datetime\n\nnow = datetime.datetime.now()\nprint(f"{now=:%Y-%m-%d %H:%M}")` },
      { title: "Chapter 28: Networking with Sockets", code: `import socket\n\nwith socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:\n    s.connect(("www.python.org", 80))` },
      { title: "Chapter 29: Interacting with APIs", code: `import requests\n\nresponse = requests.get('https://api.github.com')\nif response.status_code == 200:\n    print('Success!')` },
      { title: "Chapter 30: Web Scraping with BeautifulSoup", code: `from bs4 import BeautifulSoup\nimport requests\n\nurl = 'https://news.ycombinator.com'\nresponse = requests.get(url)\n\nsoup = BeautifulSoup(response.text, 'html.parser')` }
    ],
  },
  html: {
    name: "HTML",
    chapters: [
      { title: "Chapter 1: Basic Structure", code: `<!DOCTYPE html>\n<html>\n<head>\n  <title>My First Page</title>\n</head>\n<body>\n  <h1>Welcome</h1>\n  <p>This is a paragraph.</p>\n</body>\n</html>` },
      { title: "Chapter 2: Forms", code: `<form action="/submit" method="post">\n  <label for="username">Username:</label>\n  <input type="text" id="username" name="username">\n  \n  <button type="submit">Submit</button>\n</form>` },
      { title: "Chapter 3: Tables", code: `<table>\n  <tr>\n    <th>Firstname</th>\n    <th>Lastname</th>\n  </tr>\n  <tr>\n    <td>Peter</td>\n    <td>Griffin</td>\n  </tr>\n</table>` },
      { title: "Chapter 4: Lists", code: `<h2>Unordered List</h2>\n<ul>\n  <li>Coffee</li>\n  <li>Tea</li>\n</ul>\n\n<h2>Ordered List</h2>\n<ol>\n  <li>First item</li>\n  <li>Second item</li>\n</ol>` },
      { title: "Chapter 5: Images", code: `<img src="image.jpg" alt="An example image" width="500" height="300">` },
      { title: "Chapter 6: Links", code: `<a href="https://www.example.com">Visit Example.com</a>` },
      { title: "Chapter 7: Div and Span", code: `<div class="container">\n  <p>This is a <span class="highlight">highlighted</span> word.</p>\n</div>` },
      { title: "Chapter 8: Semantic HTML", code: `<header>\n  <h1>My Website</h1>\n</header>\n<nav>\n  <a href="/">Home</a>\n</nav>\n<main>\n  <article>\n    <h2>Article Title</h2>\n  </article>\n</main>\n<footer>\n  <p>Copyright 2024</p>\n</footer>` },
      { title: "Chapter 9: Audio and Video", code: `<video controls width="250">\n  <source src="/media/cc0-videos/flower.webm" type="video/webm">\n</video>\n\n<audio controls>\n  <source src="horse.ogg" type="audio/ogg">\n</audio>` },
      { title: "Chapter 10: Iframe", code: `<iframe src="https://www.openstreetmap.org/export/embed.html" width="425" height="350"></iframe>` },
      { title: "Chapter 11: Canvas", code: `<canvas id="myCanvas" width="200" height="100" style="border:1px solid #000;"></canvas>` },
      { title: "Chapter 12: SVG", code: `<svg width="100" height="100">\n  <circle cx="50" cy="50" r="40" stroke="green" stroke-width="4" fill="yellow" />\n</svg>` },
      { title: "Chapter 13: Details and Summary", code: `<details>\n  <summary>Click to see details</summary>\n  <p>Here are some details you can now see.</p>\n</details>` },
      { title: "Chapter 14: Figure and Figcaption", code: `<figure>\n  <img src="pic_trulli.jpg" alt="Trulli" style="width:100%">\n  <figcaption>Fig.1 - Trulli, Puglia, Italy.</figcaption>\n</figure>` },
      { title: "Chapter 15: Input Types", code: `<input type="date">\n<input type="color">\n<input type="range" min="0" max="100">\n<input type="file">` },
      { title: "Chapter 16: Data Attributes", code: `<div id="user" data-id="12345" data-user="johndoe">John Doe</div>` },
      { title: "Chapter 17: Meta Tags", code: `<head>\n  <meta charset="UTF-8">\n  <meta name="description" content="Free Web tutorials">\n  <meta name="keywords" content="HTML, CSS, JavaScript">\n  <meta name="author" content="John Doe">\n  <meta name="viewport" content="width=device-width, initial-scale=1.0">\n</head>` },
      { title: "Chapter 18: Select Element", code: `<label for="cars">Choose a car:</label>\n<select id="cars" name="cars">\n  <option value="volvo">Volvo</option>\n  <option value="saab">Saab</option>\n</select>` },
      { title: "Chapter 19: Textarea", code: `<textarea name="message" rows="10" cols="30">\n  The cat was playing in the garden.\n</textarea>` },
      { title: "Chapter 20: Button Element", code: `<button type="button" onclick="alert('Hello world!')">Click Me</button>` },
      { title: "Chapter 21: Label Element", code: `<label for="fname">First name:</label><br>\n<input type="text" id="fname" name="fname"><br>` },
      { title: "Chapter 22: Fieldset and Legend", code: `<fieldset>\n  <legend>Personalia:</legend>\n  <label for="fname">First name:</label>\n  <input type="text" id="fname" name="fname">\n</fieldset>` },
      { title: "Chapter 23: Datalist", code: `<input list="browsers">\n<datalist id="browsers">\n  <option value="Edge">\n  <option value="Firefox">\n  <option value="Chrome">\n</datalist>` },
      { title: "Chapter 24: Progress and Meter", code: `<label for="file">Downloading progress:</label>\n<progress id="file" value="32" max="100"> 32% </progress>\n\n<meter id="disk_c" value="2" min="0" max="10">2 out of 10</meter>` },
      { title: "Chapter 25: Blockquote", code: `<blockquote cite="http://www.worldwildlife.org/who/index.html">\n  For 50 years, WWF has been protecting the future of nature.\n</blockquote>` },
      { title: "Chapter 26: Abbreviation", code: `<p>The <abbr title="World Health Organization">WHO</abbr> was founded in 1948.</p>` },
      { title: "Chapter 27: Address", code: `<address>\n  Written by John Doe.<br>\n  Visit us at:<br>\n  Example.com\n</address>` },
      { title: "Chapter 28: Time Element", code: `<p>Open from <time>10:00</time> to <time>21:00</time> every weekday.</p>` },
      { title: "Chapter 29: Code and Pre", code: `<pre>\n<code>\nfunction hello() {\n  console.log("Hello");\n}\n</code>\n</pre>` },
      { title: "Chapter 30: Template Tag", code: `<template>\n  <h2>Flower</h2>\n  <img src="img_white_flower.jpg" width="214" height="204">\n</template>` }
    ],
  },
  cpp: {
    name: "C++",
    chapters: [
      { title: "Chapter 1: Basic I/O", code: `#include <iostream>\n#include <string>\n\nint main() {\n    std::string name;\n    std::cout << "Enter your name: ";\n    std::cin >> name;\n    std::cout << "Hello, " << name << "!" << std::endl;\n    return 0;\n}` },
      { title: "Chapter 2: Vectors", code: `#include <iostream>\n#include <vector>\n\nint main() {\n    std::vector<int> numbers = {1, 2, 3, 4, 5};\n    for (int num : numbers) {\n        std::cout << num << " ";\n    }\n    std::cout << std::endl;\n    return 0;\n}` },
      { title: "Chapter 3: Functions", code: `#include <iostream>\n\nint add(int a, int b) {\n    return a + b;\n}\n\nint main() {\n    int result = add(10, 20);\n    std::cout << "The sum is: " << result << std::endl;\n    return 0;\n}` },
      { title: "Chapter 4: Classes", code: `class Rectangle {\n    int width, height;\n  public:\n    void set_values(int,int);\n    int area() {return width*height;}\n};\n\nvoid Rectangle::set_values(int x, int y) {\n  width = x;\n  height = y;\n}` },
      { title: "Chapter 5: Pointers", code: `#include <iostream>\n\nint main() {\n    int var = 20;\n    int *ip;\n    ip = &var;\n\n    std::cout << "Address: " << ip << std::endl;\n    std::cout << "Value: " << *ip << std::endl;\n    return 0;\n}` },
      { title: "Chapter 6: References", code: `#include <iostream>\n\nint main () {\n   int i = 5;\n   int& r = i;\n   r = 10;\n   std::cout << "Value of i: " << i << std::endl;\n   return 0;\n}` },
      { title: "Chapter 7: File I/O", code: `#include <fstream>\n#include <iostream>\n\nint main () {\n   std::ofstream outfile("test.txt");\n   outfile << "Writing to a file." << std::endl;\n   outfile.close();\n   return 0;\n}` },
      { title: "Chapter 8: Inheritance", code: `class Shape {\n   public:\n      void setWidth(int w) { width = w; }\n   protected:\n      int width;\n};\n\nclass Square: public Shape {\n   public:\n      int getArea() { return width * width; }\n};` },
      { title: "Chapter 9: Polymorphism", code: `class Animal {\n  public:\n    void animalSound() {\n      std::cout << "The animal makes a sound \\n";\n    }\n};\n\nclass Pig : public Animal {\n  public:\n    void animalSound() {\n      std::cout << "The pig says: wee wee \\n";\n    }\n};` },
      { title: "Chapter 10: Structs", code: `struct Person {\n    std::string name;\n    int age;\n};\n\nint main() {\n    Person p1;\n    p1.name = "Bjarne";\n    p1.age = 73;\n}` },
      { title: "Chapter 11: Enums", code: `enum Color { RED, GREEN, BLUE };\n\nint main() {\n    Color myColor = BLUE;\n    if (myColor == BLUE) {\n        std::cout << "It's blue!" << std::endl;\n    }\n    return 0;\n}` },
      { title: "Chapter 12: Templates", code: `template <typename T>\nT const& max(T const& a, T const& b) {\n    return a < b ? b : a;\n}\n\nint main() {\n    std::cout << max(5, 10) << std::endl;\n}` },
      { title: "Chapter 13: Namespaces", code: `namespace first_space {\n   void func() {\n      std::cout << "Inside first_space" << std::endl;\n   }\n}\n\nusing namespace first_space;\nint main() { func(); }` },
      { title: "Chapter 14: Standard Template Library (STL)", code: `#include <map>\n\nint main() {\n    std::map<char, int> mymap;\n    mymap['a'] = 10;\n    mymap['b'] = 20;\n    std::cout << "Value of 'a' is " << mymap['a'] << std::endl;\n}` },
      { title: "Chapter 15: Exception Handling", code: `#include <iostream>\n\nint main() {\n    try {\n       throw 20;\n    } catch (int e) {\n       std::cout << "An exception occurred. " << e << std::endl;\n    }\n    return 0;\n}` },
      { title: "Chapter 16: Operator Overloading", code: `class Box {\n   public:\n      Box operator+(const Box& b) {\n         Box box;\n         box.length = this->length + b.length;\n         return box;\n      }\n   private:\n      double length;\n};` },
      { title: "Chapter 17: Smart Pointers", code: `#include <memory>\n\nint main() {\n    std::unique_ptr<int> p1(new int(5));\n    std::shared_ptr<int> p2 = std::make_shared<int>(10);\n    return 0;\n}` },
      { title: "Chapter 18: Multithreading", code: `#include <thread>\n\nvoid foo() {\n    // do something\n}\n\nint main() {\n    std::thread t1(foo);\n    t1.join();\n    return 0;\n}` },
      { title: "Chapter 19: Lambda Functions", code: `#include <vector>\n#include <algorithm>\n\nint main() {\n    std::vector<int> v {4, 1, 3, 5, 2};\n    std::sort(v.begin(), v.end(), [](int a, int b) {\n        return a < b;\n    });\n}` },
      { title: "Chapter 20: Ranged-based for loop", code: `int my_numbers[] = {1, 2, 3, 4, 5};\nfor (int i : my_numbers)\n{\n  std::cout << i << " ";\n}` },
      { title: "Chapter 21: Auto keyword", code: `auto x = 5; // x is an int\nauto y = 3.14; // y is a double\nauto z = "hello"; // z is a const char*` },
      { title: "Chapter 22: Constexpr", code: `constexpr int square(int x) {\n    return x * x;\n}\n\nint main() {\n    const int val = square(5);\n    return 0;\n}` },
      { title: "Chapter 23: Type Casting", code: `double d = 3.14;\nint i = static_cast<int>(d);\n\nclass Base {};\nclass Derived : public Base {};\nDerived* d_ptr = new Derived();\nBase* b_ptr = dynamic_cast<Base*>(d_ptr);` },
      { title: "Chapter 24: Preprocessor Directives", code: `#define PI 3.14159\n\n#ifdef DEBUG\n   std::cout << "Debugging is enabled." << std::endl;\n#endif` },
      { title: "Chapter 25: Virtual Functions", code: `class Base {\npublic:\n    virtual void print() { std::cout << "Base" << std::endl; }\n};\n\nclass Derived : public Base {\npublic:\n    void print() override { std::cout << "Derived" << std::endl; }\n};` },
      { title: "Chapter 26: Friend Functions", code: `class MyClass {\n    int secret;\n    friend void reveal(MyClass&);\n};\n\nvoid reveal(MyClass& obj) {\n    std::cout << obj.secret;\n}` },
      { title: "Chapter 27: Filesystem Library", code: `#include <filesystem>\nnamespace fs = std::filesystem;\n\nint main() {\n    fs::path p = "/";\n    std::cout << p << " exists: " << fs::exists(p) << std::endl;\n}` },
      { title: "Chapter 28: Chrono Library", code: `#include <chrono>\n#include <thread>\n\nint main() {\n    auto start = std::chrono::high_resolution_clock::now();\n    std::this_thread::sleep_for(std::chrono::seconds(1));\n    auto end = std::chrono::high_resolution_clock::now();\n}` },
      { title: "Chapter 29: Move Semantics", code: `std::string str = "Hello";\nstd::vector<std::string> v;\nv.push_back(std::move(str)); // efficiently move str into v` },
      { title: "Chapter 30: Concurrency with Futures", code: `#include <future>\n\nint find_the_answer() { return 42; }\n\nint main() {\n    std::future<int> the_answer = std::async(find_the_answer);\n    std::cout << "The answer is " << the_answer.get() << std::endl;\n}` }
    ],
  },
  typescript: {
    name: "TypeScript",
    chapters: [
      { title: "Chapter 1: Basic Types", code: `let isDone: boolean = false;\nlet decimal: number = 6;\nlet color: string = "blue";\nlet list: number[] = [1, 2, 3];` },
      { title: "Chapter 2: Interfaces", code: `interface Person {\n  name: string;\n  age: number;\n}\n\nfunction greet(person: Person) {\n  return "Hello, " + person.name;\n}` },
      { title: "Chapter 3: Classes", code: `class Greeter {\n  greeting: string;\n  constructor(message: string) {\n    this.greeting = message;\n  }\n  greet() {\n    return "Hello, " + this.greeting;\n  }\n}` },
      { title: "Chapter 4: Enums", code: `enum Color {Red, Green, Blue}\nlet c: Color = Color.Green;` },
      { title: "Chapter 5: Generics", code: `function identity<T>(arg: T): T {\n  return arg;\n}\n\nlet output = identity<string>("myString");` },
      { title: "Chapter 6: Type Aliases", code: `type Point = {\n  x: number;\n  y: number;\n};\n\nfunction logPoint(p: Point) {\n  console.log(p.x, p.y);\n}` },
      { title: "Chapter 7: Union Types", code: `function padLeft(value: string, padding: string | number) {\n  // ...\n}` },
      { title: "Chapter 8: Intersection Types", code: `interface Draggable { drag: () => void; }\ninterface Resizable { resize: () => void; }\n\ntype UIElement = Draggable & Resizable;` },
      { title: "Chapter 9: Literal Types", code: `let x: "hello";\nx = "hello";\n// x = "howdy"; // Error` },
      { title: "Chapter 10: Modules", code: `export const pi = 3.14;\n\nimport { pi } from "./math";\nconsole.log(pi);` },
      { title: "Chapter 11: Decorators", code: `@sealed\nclass BugReport {\n  type = "report";\n  title: string;\n\n  constructor(t: string) {\n    this.title = t;\n  }\n}` },
      { title: "Chapter 12: Mixins", code: `class Disposable { isDisposed: boolean; }\nclass Activatable { isActive: boolean; }\n\nclass SmartObject implements Disposable, Activatable { }` },
      { title: "Chapter 13: Namespaces", code: `namespace Validation {\n  export interface StringValidator { isAcceptable(s: string): boolean; }\n}` },
      { title: "Chapter 14: Utility Types", code: `interface Todo { title: string; }\n\nconst todo: Readonly<Todo> = {\n  title: "Delete inactive users",\n};` },
      { title: "Chapter 15: Advanced Types", code: `type Easing = "ease-in" | "ease-out" | "ease-in-out";\nclass UIElement {\n  animate(options: { easing: Easing }) {}\n}` },
      { title: "Chapter 16: Async/Await", code: `async function getTodo() {\n    const response = await fetch('https://jsonplaceholder.typicode.com/todos/1');\n    const todo: Todo = await response.json();\n    return todo;\n}` },
      { title: "Chapter 17: Conditional Types", code: `type Check<T> = T extends string ? boolean : number;\ntype A = Check<string>; // boolean\ntype B = Check<number>; // number` },
      { title: "Chapter 18: Mapped Types", code: `type Readonly<T> = { readonly [P in keyof T]: T[P]; };` },
      { title: "Chapter 19: Type Guards", code: `function isFish(pet: Fish | Bird): pet is Fish {\n  return (pet as Fish).swim !== undefined;\n}` },
      { title: "Chapter 20: Discriminated Unions", code: `interface Square { kind: "square"; size: number; }\ninterface Circle { kind: "circle"; radius: number; }\ntype Shape = Square | Circle;` },
      { title: "Chapter 21: Never Type", code: `function error(message: string): never {\n  throw new Error(message);\n}` },
      { title: "Chapter 22: Index Signatures", code: `interface StringArray {\n  [index: number]: string;\n}\nconst myArray: StringArray = ["Bob", "Fred"];` },
      { title: "Chapter 23: Keyof Operator", code: `type PointKeys = keyof Point; // "x" | "y"` },
      { title: "Chapter 24: Typeof Operator", code: `let s = "hello";\nlet n: typeof s; // n is a string` },
      { title: "Chapter 25: Tuple Types", code: `let x: [string, number];\nx = ["hello", 10];` },
      { title: "Chapter 26: Ambient Declarations", code: `declare var jQuery: (selector: string) => any;` },
      { title: "Chapter 27: Project References", code: `// tsconfig.json\n{\n    "references": [\n        { "path": "../common" }\n    ]\n}` },
      { title: "Chapter 28: Declaration Merging", code: `interface Box {\n  height: number;\n  width: number;\n}\ninterface Box {\n  scale: number;\n}` },
      { title: "Chapter 29: ts-ignore", code: `// @ts-ignore\nconst value: string = 123; // This will not cause a compile error` },
      { title: "Chapter 30: JSDoc Support", code: `/**\n * @param {string} name The name of the person to greet.\n */\nfunction greet(name) {\n  console.log(\`Hello, \${name}!\`);\n}` }
    ],
  },
  c: {
    name: "C",
    chapters: [
      { title: "Chapter 1: Hello World", code: `#include <stdio.h>\n\nint main() {\n   printf("Hello, World!\\n");\n   return 0;\n}` },
      { title: "Chapter 2: Variables and Types", code: `int myNum = 5;            // Integer\nfloat myFloatNum = 5.99;  // Floating point number\nchar myLetter = 'D';      // Character` },
      { title: "Chapter 3: Arrays", code: `int myNumbers[] = {25, 50, 75, 100};\nprintf("%d", myNumbers[0]);` },
      { title: "Chapter 4: Pointers", code: `int myAge = 43;\nint* ptr = &myAge;\nprintf("%p\\n", (void*)ptr);\nprintf("%d\\n", *ptr);` },
      { title: "Chapter 5: Strings", code: `char greetings[] = "Hello World!";\nprintf("%s", greetings);` },
      { title: "Chapter 6: User Input", code: `int myNum;\nprintf("Type a number: ");\nscanf("%d", &myNum);` },
      { title: "Chapter 7: Conditionals", code: `if (20 > 18) {\n  printf("20 is greater than 18");\n}` },
      { title: "Chapter 8: Loops", code: `int i;\nfor (i = 0; i < 5; i++) {\n  printf("%d\\n", i);\n}` },
      { title: "Chapter 9: Functions", code: `void myFunction() {\n  printf("I just got executed!");\n}\n\nint main() {\n  myFunction();\n  return 0;\n}` },
      { title: "Chapter 10: Structs", code: `struct myStructure {\n  int myNum;\n  char myLetter;\n};\n\nint main() {\n  struct myStructure s1;\n  return 0;\n}` },
      { title: "Chapter 11: File Handling", code: `FILE *fptr;\nfptr = fopen("filename.txt", "w");\nfprintf(fptr, "Some text");\nfclose(fptr);` },
      { title: "Chapter 12: Dynamic Memory Allocation", code: `#include <stdlib.h>\n\nint* ptr;\nptr = (int*) malloc(5 * sizeof(int));\nfree(ptr);` },
      { title: "Chapter 13: Enums", code: `enum Level {\n  LOW,\n  MEDIUM,\n  HIGH\n};\n\nenum Level myVar = MEDIUM;` },
      { title: "Chapter 14: Preprocessor Directives", code: `#define PI 3.14159\n\n#include <stdio.h>` },
      { title: "Chapter 15: Header Files", code: `// myheader.h\nvoid my_function(void);\n\n// main.c\n#include "myheader.h"` },
      { title: "Chapter 16: Recursion", code: `int sum(int k) {\n  if (k > 0) {\n    return k + sum(k - 1);\n  } else {\n    return 0;\n  }\n}` },
      { title: "Chapter 17: Bitwise Operators", code: `unsigned int a = 60;  // 0011 1100\nunsigned int b = 13;  // 0000 1101\nint c = a & b;      // 0000 1100` },
      { title: "Chapter 18: Unions", code: `union Data {\n   int i;\n   float f;\n   char str[20];\n};\n\nunion Data data;` },
      { title: "Chapter 19: Function Pointers", code: `void my_int_func(int x) {}\nvoid (*foo)(int);\nfoo = &my_int_func;` },
      { title: "Chapter 20: Static Variables", code: `void func(void) {\n   static int i = 5; \n   i++;\n}` },
      { title: "Chapter 21: Typedef", code: `typedef unsigned char BYTE;\nBYTE b1, b2;` },
      { title: "Chapter 22: Error Handling", code: `#include <errno.h>\n#include <string.h>\n\nFILE *fp = fopen("none.txt", "r");\nif (fp == NULL) {\n  fprintf(stderr, "Error: %s\\n", strerror(errno));\n}` },
      { title: "Chapter 23: Command Line Arguments", code: `int main(int argc, char *argv[]) {\n  printf("Argument count: %d\\n", argc);\n  return 0;\n}` },
      { title: "Chapter 24: Macros", code: `#define MAX(x, y) (((x) > (y)) ? (x) : (y))` },
      { title: "Chapter 25: Volatile Keyword", code: `volatile int counter = 0;` },
      { title: "Chapter 26: Extern Keyword", code: `// first file: main.c\nint count;\n\n// second file: support.c\nextern int count;` },
      { title: "Chapter 27: Const Keyword", code: `const int LENGTH = 10;` },
      { title: "Chapter 28: Multithreading (pthreads)", code: `#include <pthread.h>\n\nvoid *myThreadFun(void *vargp) {\n   return NULL;\n}\n\nint main() {\n   pthread_t thread_id;\n   pthread_create(&thread_id, NULL, myThreadFun, NULL);\n   pthread_join(thread_id, NULL);\n}` },
      { title: "Chapter 29: Sockets", code: `#include <sys/socket.h>\n\nint sockfd = socket(AF_INET, SOCK_STREAM, 0);` },
      { title: "Chapter 30: Signal Handling", code: `#include <signal.h>\n\nvoid sighandler(int signum) {}\n\nsignal(SIGINT, sighandler);` }
    ],
  },
};