for (let x in y) loop code example

Example 1: javascript loop object

let obj = {
  key1: "value1",
  key2: "value2",
  key3: "value3"
}

Object.keys(obj).forEach(key => {
    console.log(key, obj[key]);
});
// key1 value1
// key2 value2
// key3 value3

// using for in - same output as above
for (let key in obj) {
  let value = obj[key];
  console.log(key, value);
}

Example 2: javascript for of

const array = ['hello', 'world', 'of', 'Corona'];

for (const item of array) {
  console.log(item);
}

Example 3: for in and for of in js

const iterable = [10, 20, 30];

for (const value of iterable) {
  console.log("fef"+value);
}
// 10
// 20
// 30