js in vs of code example

Example 1: for of vs for in javascript

let list = [4, 5, 6];

for (let i in list) {
   console.log(i); // "0", "1", "2",
}

for (let i of list) {
   console.log(i); // "4", "5", "6"
}

// EXAMPLE 2
let pets = new Set(["Cat", "Dog", "Hamster"]);
pets["species"] = "mammals";

for (let pet in pets) {
   console.log(pet); // "species"
}

for (let pet of pets) {
    console.log(pet); // "Cat", "Dog", "Hamster"
}

Example 2: for in and for of in js

let iterable = new Map([["a", 1], ["b", 2], ["c", 3]]);

for (let entry of iterable) {
  console.log(entry);
}
// [a, 1]
// [b, 2]
// [c, 3]

for (let [key, value] of iterable) {
  console.log(value);
}
// 1
// 2
// 3