Javascript for iteration

js-for-iteration.js

let myArray = [1, 2, 3, 4];

// This iterates over contents of container. This is not applicable for objects.
for (item of myArray) {
    console.log(item); // 1, 2, 3, 4
}

let myObject = {
    first: 1,
    second: 2
};

// This can only be used in objects.
for (item in myObject) {
    console.log(`${item} => ${myObject[item]}`); // first => 1, second => 2
}