JavaScript Objects

Creating Objects

const person = {
    name: "Alice",
    age: 25,
    greet() {
        return `Hi, I am ${this.name}`;
    }
};
console.log(person.name);      // Alice
console.log(person["age"]);    // 25
console.log(person.greet());   // Hi, I am Alice

Destructuring

const { name, age } = person;
console.log(name); // Alice

// With rename
const { name: fullName } = person;

// Default values
const { city = "Unknown" } = person;

Spread with Objects

const defaults = { color: "blue", size: "M" };
const custom   = { size: "L", weight: "light" };
const merged   = { ...defaults, ...custom };
// { color: "blue", size: "L", weight: "light" }

Classes (ES6+)

class Animal {
    constructor(name, sound) {
        this.name = name;
        this.sound = sound;
    }
    speak() {
        return `${this.name} says ${this.sound}!`;
    }
}

class Dog extends Animal {
    constructor(name) {
        super(name, "woof");
    }
    fetch() { return `${this.name} fetches the ball!`; }
}

const rex = new Dog("Rex");
console.log(rex.speak());  // Rex says woof!