Projects: Module 01 — Introduction to JavaScript¶

Project ideas appropriate for a JavaScript beginner who has completed Module 01. These projects use only the concepts from this module: variables, types, functions, control flow, and basic string/array operations. For more ambitious projects (React, TypeScript, APIs), see the topic-level PROJECTS.md.

Project 1: Number Guessing Game¶

Difficulty: Beginner Estimated Time: 2–3 hours Concepts Practiced: Variables, functions, loops, conditionals, user input (Node.js readline)

Description: Build a command-line number guessing game. The program picks a random integer between 1 and 100. The user guesses, and the program tells them "too high", "too low", or "correct!" and counts how many guesses it took.

Requirements: - Use Math.random() and Math.floor() to pick a random number - Accept user input from the command line using Node.js readline module - Give appropriate hints after each guess - Track and display the number of guesses on success - Ask if the player wants to play again

Stretch goals: - Add difficulty levels: Easy (1–50, 10 guesses), Medium (1–100, 7 guesses), Hard (1–200, 7 guesses) - Maintain a high score (fewest guesses) across multiple rounds using a variable

Project 2: FizzBuzz Variations¶

Difficulty: Beginner Estimated Time: 1–2 hours Concepts Practiced: Loops, conditionals, modulo operator, arrays, functions

Description: The classic FizzBuzz problem, extended with variations to build your loop and conditional skills.

Requirements: 1. Write the classic FizzBuzz: print numbers 1–100, replacing multiples of 3 with "Fizz", multiples of 5 with "Buzz", and multiples of both with "FizzBuzz". 2. Generalize it: write a fizzBuzz(n, rules) function where rules is an array like [{divisor: 3, word: "Fizz"}, {divisor: 5, word: "Buzz"}]. It should work for any combination of divisors and words. 3. Write a fizzBuzzCount(n) function that returns an object with the count of each category: { fizz: X, buzz: X, fizzbuzz: X, other: X }.

Project 3: Text Analyzer¶

Difficulty: Beginner Estimated Time: 3–4 hours Concepts Practiced: Strings, arrays, loops, functions, objects as dictionaries

Description: Build a text analysis utility that processes a string of text and produces statistics.

Requirements: - Word count (split by whitespace) - Character count (with and without spaces) - Sentence count (split by ., !, ?) - Most frequent word(s) — build a frequency map using an object - Average word length - Longest word

Example usage:

const text = "JavaScript is great. JavaScript is fun. I love JavaScript.";
const stats = analyze(text);
console.log(stats);
// {
//   wordCount: 11,
//   charCount: 58,
//   charCountNoSpaces: 48,
//   sentenceCount: 3,
//   mostFrequentWord: 'javascript',
//   topWordCount: 3,
//   averageWordLength: 4.4,
//   longestWord: 'javascript'
// }

Stretch goal: Accept the text as a command-line argument (process.argv[2]) so you can analyze any string without editing the code.

Project 4: Mini Calculator REPL¶

Difficulty: Beginner–Intermediate Estimated Time: 4–6 hours Concepts Practiced: Functions, strings, parsing, loops, switch/conditionals, Node.js readline

Description: Build an interactive calculator that runs in the terminal. Users type expressions like 5 + 3 and see the result immediately. The calculator keeps running until the user types exit.

Requirements: - Accept input in the format <number> <operator> <number> (e.g., 10 * 4) - Support at least +, -, *, /, and % (modulo) - Handle division by zero with a friendly error message - Keep a history of all calculations in the current session - Support a history command to show all previous calculations - Support clear to reset history - Support exit to quit

Stretch goals: - Add memory: memory set saves the last result, memory get retrieves it - Support chaining: 5 + 3 * 2 (with correct operator precedence)