Q35. What are getters and setters in JavaScript?

const user = {
  firstName: "Rahim",
  lastName: "Karim",

  get fullName() {
    return this.firstName + " " + this.lastName;
  },
};

console.log(user.fullName); // "Rahim Karim" — পড়লে getter চলে
console.log(user.firstName); // "Rahim" — সাধারণ প্রপার্টি

const temperature = {
  celsius: 20,

  get fahrenheit() {
    return this.celsius * 9 / 5 + 32;
  },

  set fahrenheit(value) {
    this.celsius = (value - 32) * 5 / 9;
  },
};

console.log(temperature.fahrenheit); // 68

temperature.fahrenheit = 212;
console.log(temperature.celsius);    // 100

class Rectangle {
  constructor(width, height) {
    this.width = width;
    this.height = height;
  }

  get area() {
    return this.width * this.height;
  }

  get isSquare() {
    return this.width === this.height;
  }
}

class User {
  #email; // সত্যিকারের private field

  constructor(name, email) {
    this.name = name;
    this.#email = email;
  }

  get email() {
    return this.#email;
  }

  set email(value) {
    if (!value.includes("@")) {
      throw new Error("সঠিক ইমেইল দিন");
    }
    this.#email = value;
  }
}

const user = new User("Rahim", "rahim@example.com");

user.email = "nope"; // Error: সঠিক ইমেইল দিন

// class ছাড়া defineProperty দিয়ে
const user = {};

Object.defineProperty(user, "name", {
  get() {
    return "Rahim";
  },
  enumerable: true,
  configurable: true,
});

console.log(user.name);           // "Rahim"
console.log(Object.keys(user));  // ["name"]