Developing Procedures Lesson 
%%js

// Homework: Developing Procedures in JavaScript

// 1. Write a procedure that takes a number and returns its cube.
function cube(n) {
  return n * n * n;
}

// 2. Write a procedure that takes an array of numbers and returns the sum.
function listSum(numbers) {
  let total = 0;
  for (let num of numbers) {
    total += num;
  }
  return total;
}

// 3. Write a procedure that checks if a word is a palindrome.
function isPalindrome(word) {
  const reversed = word.split('').reverse().join('');
  return word === reversed;
}

// Test the functions
console.log(cube(3)); // 27

const nums = [1, 2, 3];
console.log(listSum(nums)); // 6

console.log(isPalindrome("racecar")); // true
console.log(isPalindrome("apple"));   // false


<IPython.core.display.Javascript object>

1. cube(n) Function

  • Purpose: This function takes a number n and returns its cube (i.e., n raised to the power of 3).
  • How it works: The function multiplies the number n by itself three times.

2. ListSum(numbers) Function

  • Purpose: This function takes an array of numbers and returns the sum of those numbers.
  • How it works: The function initializes a total variable to 0, then loops through each number in the array numbers using a for…of loop. In each iteration, the current number is added to total.

3. isPalindrome(word) Function

  • Purpose: This function checks if a given word is a palindrome, meaning it reads the same forwards and backwards.
  • How it works: The function splits the word into an array of characters word.split(), reverses that array reverse(), then joins the characters back together into a string join(). Finally, it checks if the reversed word is the same as the original word.

Console Output:

The console.log statements test the functions:

  • cube(3) prints 27, as it returns the cube of 3.
  • listSum([1, 2, 3]) prints 6, as it returns the sum of 1, 2, and 3.
  • isPalindrome(racecar) prints true, as racecar is a palindrome.
  • isPalindrome(apple) prints false, as apple is not a palindrome.