অবজেক্ট (Objects)

// Creating an object
let player = {
  name: "Laboni",
  level: 12,
  health: 95,
  isAlive: true,
  inventory: ["sword", "shield", "potion"]
};

// Accessing properties — two ways:
console.log(player.name);        // "Laboni" (dot notation)
console.log(player["level"]);    // 12 (bracket notation)

// Bracket notation is required for:
// 1. Dynamic keys (from variables)
let key = "health";
console.log(player[key]);        // 95

// 2. Keys with spaces or special characters
let weird = { "full name": "Laboni Akter" };
console.log(weird["full name"]); // "Laboni Akter"

// Adding new properties
player.score = 2500;
console.log(player.score); // 2500

// Deleting properties
delete player.isAlive;
console.log(player.isAlive); // undefined

Laboni
12
95
Luna Star
2500
undefined

let dog = {
  name: "Pixel",
  breed: "Corgi",
  energy: 100,
  // Method — shorthand syntax
  bark() {
    console.log(`${this.name} says: Woof!`);
  },
  play() {
    this.energy -= 20;
    console.log(`${this.name} played! Energy: ${this.energy}`);
  }
};

dog.bark();  // "Pixel says: Woof!"
dog.play();  // "Pixel played! Energy: 80"
dog.play();  // "Pixel played! Energy: 60"

// Computed property names
let field = "color";
let shirt = { [field]: "blue", size: "M" };
console.log(shirt.color); // "blue"

// Shorthand: when variable name matches key name
let x = 10, y = 20;
let point = { x, y }; // same as { x: x, y: y }
console.log(point);    // { x: 10, y: 20 }

Pixel says: Woof!
Pixel played! Energy: 80
Pixel played! Energy: 60
blue
{ x: 10, y: 20 }

let movie = { title: "Inception", year: 2010, rating: 8.8 };

// Destructuring — pull out properties
let { title, year } = movie;
console.log(title); // "Inception"
console.log(year);  // 2010

// Rename while destructuring
let { rating: score } = movie;
console.log(score); // 8.8

// Default values
let { director = "Unknown" } = movie;
console.log(director); // "Unknown" (movie has no 'director' key)

// Spread — copy and merge objects
let base = { a: 1, b: 2 };
let extra = { b: 99, c: 3 };
let merged = { ...base, ...extra };
console.log(merged); // { a: 1, b: 99, c: 3 } (later values win!)

// Object.keys, values, entries
let pet = { name: "Mochi", type: "cat", age: 3 };
console.log(Object.keys(pet));    // ["name", "type", "age"]
console.log(Object.values(pet));  // ["Mochi", "cat", 3]

// Loop over entries
for (let [key, value] of Object.entries(pet)) {
  console.log(`${key}: ${value}`);
}

Inception
2010
8.8
Unknown
{ a: 1, b: 99, c: 3 }
["name", "type", "age"]
["Mochi", "cat", 3]
name: Mochi
type: cat
age: 3