const numbers = [1, 2, 3, 4, 5];

const result = numbers
  .map(n => n * 2)
  .filter(n => n > 5)
  .reduce((acc, n, index) => {
    acc.sum += n;
    acc.indices.push(index);
    return acc;
  }, { sum: 0, indices: [] });

console.log(result.sum);
console.log(result.indices);

const a = { value: 1 };
const b = Object.create(a);
b.value = 2;

console.log(b.value);
console.log(a.value);

class Counter {
  constructor(max) {
    this.max = max;
  }
  
  *[Symbol.iterator]() {
    let current = 0;
    while (current < this.max) {
      yield current++;
    }
  }
}

const counter = new Counter(3);
const result = [...counter, ...counter];
console.log(result);

var str="My name is John";
var words1=str.split(" ",3);
console.log("words1:",words1);
var words2=str.split(" ",5);
console.log("words2:",words2);

const fruits = ['apple', 'banana', 'cherry'];
const newFruits = [...fruits];

newFruits.push('date');

const user = { name: 'Taylor', age: 30 };
const updatedUser = { ...user, age: 31 };

user.city = 'Seattle';

console.log(fruits.length, newFruits.length, user.city, updatedUser.city);

function* infiniteGenerator() {
  let i = 0;
  while (true) {
    yield i++;
  }
}

const weakMap = new WeakMap();
const gen = infiniteGenerator();

weakMap.set(gen, gen.next().value);

const result = weakMap.get(gen) + gen.next().value;

console.log(result);

const person = {
  name: "John",
  greet: function() {
    const getMessage = () => `Hello, ${this.name}`;
    return getMessage();
  }
};

console.log(person.greet());

function* createCounter() {
  let count = 0;
  while (true) {
    const reset = yield ++count;
    if (reset) {
      count = 0;
    }
  }
}

const counter = createCounter();
console.log(counter.next().value);
console.log(counter.next().value);
console.log(counter.next(true).value);
console.log(counter.next().value);

const cache = new WeakMap();

const user1 = { name: 'Alice' };
const user2 = { name: 'Bob' };

cache.set(user1, { lastLogin: 'yesterday' });
cache.set(user2, { lastLogin: 'today' });

const result = [];
result.push(cache.has(user1));
result.push(cache.get(user2).lastLogin);

let user3 = { name: 'Charlie' };
cache.set(user3, { lastLogin: 'now' });
result.push(cache.has(user3));

user3 = null; // Removing the reference
// Garbage collector might run here in real situations

const user4 = { name: 'Charlie' }; // Same name, different object
result.push(cache.has(user4));

console.log(result);

const obj = {
  name: 'Sarah',
  getName() {
    return this.name;
  },
  getNameArrow: () => {
    return this.name;
  }
};

const getName = obj.getName;
const getNameArrow = obj.getNameArrow;

console.log(obj.getName());
console.log(getName());
console.log(getNameArrow());
console.log(obj.getNameArrow());

const person = {
  name: "John",
  greet: function() {
    const getMessage = () => `Hello, ${this.name}`;
    return getMessage();
  }
};

console.log(person.greet());

function a() {
   console.log(arguments[0]);
}

a([1]);

const handler = {
  get(target, prop) {
    if (prop in target) {
      return target[prop] * 2;
    } else {
      return `Property ${prop} not found`;
    }
  },
  set(target, prop, value) {
    if (typeof value === 'number') {
      target[prop] = Math.round(value);
      return true;
    }
    return false;
  }
};

const obj = { a: 5, b: 10 };
const proxy = new Proxy(obj, handler);

proxy.c = 7.8;
proxy.d = "hello";

console.log(obj.c, proxy.a, proxy.x);

const numbers = [0,0,0];

let i = 0;
const result = numbers.reduce((acc, _) => {
  return ++acc;
}, i);

console.log(i, result);

const numbers = [1, 2, 3, 4, 5];

const result = numbers
  .map(n => n * 2)
  .filter(n => n > 5)
  .reduce((acc, n, index) => {
    acc.sum += n;
    acc.indices.push(index);
    return acc;
  }, { sum: 0, indices: [] });

console.log(result.sum);
console.log(result.indices);

console.log('Start');

setTimeout(() => {
  console.log('Timeout 1');
}, 0);

Promise.resolve().then(() => {
  console.log('Promise 1');
}).then(() => {
  console.log('Promise 2');
});

setTimeout(() => {
  console.log('Timeout 2');
}, 0);

console.log('End');