Below are various ways of neat commenting:

let x = 99;    // assign numerical value to x
let y = x + 2; // assign the sum of x + 2 to y

// Print "Hello, World!" to the console
console.log("Hello, World!");

// Function to add two numbers
function addTwoNumbers(x, y) {
  let sum = x + y;
  return sum;
}  

// Initialize a function
function alphabetizeOceans() {
    // Define oceans variable as a list of strings
    const oceans = ["Pacific", "Atlantic", "Indian", "Antarctic", "Arctic"];

    // Print alphabetized array to the console
    console.log(oceans.sort());
}

/* Initialize and invoke a the greetUser function
to assign user's name to a constant and print out
a greeting. */

function greetUser() {
  const name = prompt("What is your name?");
  console.log("Hello ," + name + "! How are you?");
}

/**
 * Initialize constant with an array of strings.
 * Loop through each item in the array and print
 * it to the console.
 */

const seaCreatures = ["Shark", "Fish", "Octopus"];

for (const seaCreature of seaCreatures) {
  console.log(seaCreature);
}