object methods in javascript

1Object.getOwnPropertyNames() 

1/// OBJECTS IN JAVASCRIPT
2const testScore = {
3  damon: 89,
4  shawn: 91,
5  keenan: 80,
6  kim: 89,
7};
8
9Object.keys(testScore);  // gives all keys
10Object.values(testScore); // gives all values
11Object.entries(testScore); // gives nested arrays of key-value pairs
12
13// YOU CAN USE ( FOR-IN )  LOOP FOR ITERATION OVER OBJECTS
14for (let person in testScore) {...} 
15
16// WE CAN'T DIRECTLY USE ( FOR-OF ) LOOP IN OBJECTS BUT WE CAN DO Like THIS:
17for(let score of Object.values(testScore)){
18  	console.log(score)  // 89 91 80 89 
19}
20
21

1objectName.methodname = functionName;
2
3var myObj = {
4  myMethod: function(params) {
5    // ...do something
6  }
7
8  // OR THIS WORKS TOO
9
10  myOtherMethod(params) {
11    // ...do something else
12  }
13};
14

1// create 2 objects for Mark and John that calculate their BMI's
2// BMI = mass / height ** 2 || mass / (height * height);
3// mass: kg
4
5// john object
6const johnObj = {
7  firstName: "John",
8  lastName: "Smith",
9  mass: 92,
10  height: 1.95,
11  calcBMI: function () {
12    // learn more about 'this' 
13    // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/this
14    this.bmi = Number((this.mass / this.height ** 2).toFixed(2));
15    return this.bmi;
16  },
17};
18
19// mark object
20const markObj = {
21  firstName: "Mark",
22  lastName: "Miller",
23  mass: 78,
24  height: 1.69,
25  calcBMI: function () {
26    this.bmi = Number((this.mass / this.height ** 2).toFixed(2));
27    return this.bmi;
28  },
29};
30
31// store the ternary results in a variable
32const results =
33  johnObj.calcBMI() > markObj.calcBMI()
34    ? `${johnObj.firstName} has a higher BMI of ${johnObj.calcBMI()} than ${
35        markObj.firstName
36      }'s BMI of ${markObj.calcBMI()}!`
37    : `${markObj.firstName} has a higher BMI of ${markObj.calcBMI()} than ${
38        johnObj.firstName
39      }'s BMI of ${johnObj.calcBMI()}!`;
40
41// display the results on the console
42console.log(results);