loop through object javascript

1Object.entries(obj).forEach(
2    ([key, value]) => console.log(key, value)
3);

1// object to loop through
2let obj = { first: "John", last: "Doe" };
3
4// loop through object and log each key and value pair
5//ECMAScript 5
6Object.keys(obj).forEach(function(key) {
7    console.log(key, obj[key]);
8});
9
10//ECMAScript 6
11for (const key of Object.keys(obj)) {
12    console.log(key, obj[key]);
13}
14
15//ECMAScript 8
16Object.entries(obj).forEach(
17    ([key, value]) => console.log(key, value)
18);
19
20// OUTPUT
21/*
22   first John
23   last Doe
24*/

1for (var property in object) {
2  if (object.hasOwnProperty(property)) {
3    // Do things here
4  }
5}
6

1var p = {
2    "p1": "value1",
3    "p2": "value2",
4    "p3": "value3"
5};
6
7// for-in
8for (var key in p) {
9    if (p.hasOwnProperty(key)) {
10        console.log(key + " -> " + p[key]);
11    }
12}
13
14// for-of with Object.keys()
15for (var key of Object.keys(p)) {
16    console.log(key + " -> " + p[key])
17}
18
19// Object.entries()
20for (let [key, value] of Object.entries(p)) {
21  console.log(`${key}: ${value}`);
22}

1const fruits = {
2  apple: 28,
3  orange: 17,
4  pear: 54,
5}
6
7const keys = Object.keys(fruits)
8console.log(keys) // [apple, orange, pear]
9

1var p = {
2    "p1": "value1",
3    "p2": "value2",
4    "p3": "value3"
5};
6
7for (var key in p) {
8    if (p.hasOwnProperty(key)) {
9        console.log(key + " -> " + p[key]);
10    }
11}