Object Basics in JavaScript

1// Method 1: Object literal
2let person = {
3    name: "John",
4    age: 30,
5    city: "New York"
6};
7
8console.log("Person:", person);
9console.log("Name:", person.name);
10console.log("Age:", person.age);
11
12// Method 2: Adding properties
13person.email = "john@example.com";
14person["phone"] = "123-456-7890";
15
16console.log("\nAfter adding properties:", person);
17
18// Method 3: Object with methods
19let calculator = {
20    num1: 10,
21    num2: 5,
22    add: function() {
23        return this.num1 + this.num2;
24    },
25    subtract: function() {
26        return this.num1 - this.num2;
27    },
28    multiply() {  // ES6 shorthand
29        return this.num1 * this.num2;
30    }
31};
32
33console.log("\nCalculator:");
34console.log("Add:", calculator.add());
35console.log("Subtract:", calculator.subtract());
36console.log("Multiply:", calculator.multiply());
37
38// Method 4: Object constructor
39function Person(name, age) {
40    this.name = name;
41    this.age = age;
42    this.greet = function() {
43        return "Hello, I'm " + this.name;
44    };
45}
46
47let person1 = new Person("Alice", 25);
48let person2 = new Person("Bob", 30);
49
50console.log("\nPerson 1:", person1.greet());
51console.log("Person 2:", person2.greet());
52
53// Method 5: Object.keys, Object.values, Object.entries
54let student = {
55    name: "Jane",
56    grade: "A",
57    subjects: ["Math", "Science"]
58};
59
60console.log("\nObject methods:");
61console.log("Keys:", Object.keys(student));
62console.log("Values:", Object.values(student));
63console.log("Entries:", Object.entries(student));
64
65// Method 6: Object destructuring
66let { name, age } = person;
67console.log("\nDestructured:", name, age);
68
69// Method 7: Spread operator
70let personCopy = { ...person };
71personCopy.age = 31;
72console.log("\nOriginal:", person.age);
73console.log("Copy:", personCopy.age);