javascript foreach in object

1const students = {
2  adam: {age: 20},
3  kevin: {age: 22},
4};
5
6Object.entries(students).forEach(student => {
7  // key: student[0]
8  // value: student[1]
9  console.log(`Student: ${student[0]} is ${student[1].age} years old`);
10});
11/* Output:
12Student: adam is 20 years old
13Student: kevin is 22 years old
14*/

1const obj = {
2  name: 'Jean-Luc Picard',
3  rank: 'Captain'
4};
5
6// Prints "name Jean-Luc Picard" followed by "rank Captain"
7Object.entries(obj).forEach(entry => {
8  const [key, value] = entry;
9  console.log(key, value);
10});

1const list = {
2  key: "value",
3  name: "lauren",
4  email: "lauren@notreally.com",
5  age: 30
6};
7
8// Object.keys returns an array of the keys
9// for the object passed in as an argument.
10
11Object.keys(list).forEach(val => {
12  let key = val;
13  let value = list[val];
14  console.log(`${key} : ${value}`);
15});
16
17// Returns:
18// "key : value"
19// "name : lauren";
20// "email : lauren@notreally.com"
21// "age : 30"
22

1const obj = {
2  a: "aa",
3  b: "bb",
4  c: "cc",
5};
6//This for loop will loop through all keys in the object.
7// You can get the value by calling the key on the object with "[]"
8for(let key in obj) {
9  console.log(key);
10  console.log(obj[key]);
11}
12
13//This will return the following:
14// a
15// aa
16// b
17// bb
18// c
19// cc

1Add thisvar 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}

1for (var key in validation_messages) {
2    // skip loop if the property is from prototype
3    if (!validation_messages.hasOwnProperty(key)) continue;
4
5    var obj = validation_messages[key];
6    for (var prop in obj) {
7        // skip loop if the property is from prototype
8        if (!obj.hasOwnProperty(prop)) continue;
9
10        // your code
11        alert(prop + " = " + obj[prop]);
12    }
13}