3.3 Javascript Mathematical Hacks

Popcorn Hacks

1. Easy
   • Create a function that uses 4 of the 5 basic arithmetic operations and returns the number 32 as the answer.
2. Medium
   • Make a function that lets you make a sandwich. Ask for different ingredients and at the end give the sandwich a name.
3. Hard
   • Create a “choose-your-own-path” type of game. There should be 2-3 different storylines the user can choose from (Ex: You see a fight at school. Do you break it up or mind your own buiness.)
   • BONUS: draw a flowchart for your code.

Example Hack 1 (Function for Basic Arithmetic Operations)

%%javascript

function basicOperations(a, b) {
    let sum = a + b;
    let difference = a - b;
    let product = a * b;
    let quotient = a / b;
    let remainder = a % b;

    console.log(`Addition: ${a} + ${b} = ${sum}`);
    console.log(`Subtraction: ${a} - ${b} = ${difference}`);
    console.log(`Multiplication: ${a} * ${b} = ${product}`);
    console.log(`Division: ${a} / ${b} = ${quotient}`);
    console.log(`Modulus: ${a} % ${b} = ${remainder}`);
}

basicOperations(10, 5);

Example Hack 2 (Fibbonaci Sequence)

function fibonacci(n) {
    if (n === 0) return 0;
    if (n === 1) return 1;
    
    let a = 0;
    let b = 1;
    let next;

    for (let i = 2; i <= n; i++) {
        next = a + b;
        a = b;
        b = next;
    }
    return b;
}

let n = 7; // Find the 7th Fibonacci number
console.log(`The ${n}th Fibonacci number is: ${fibonacci(n)}`);

Homework Hacks

After learning about Mathmatical Expressions and Operations in JavaScript, you should be able to complete the hacks listed below…

1. Write a function that takes two variables a and b. The function should:
   • Compute the Greatest Common Divisor (GCD) of a and b.
   • Compute the Least Common Multiple (LCM) of a and b.
   • Return both results as an object.
2. Write a function that takes a positive integer n and returns an array of its prime factors. Prime factors are the prime numbers that divide n exactly, without leaving a remainder. If n is a prime number, the array should simply contain n.