const obj = {
  data: ['x', 'y', 'z'],
  *[Symbol.iterator]() {
    for (let i = this.data.length - 1; i >= 0; i--) {
      yield this.data[i].toUpperCase();
    }
  }
};

const result = [];
for (const item of obj) {
  result.push(item);
  if (result.length === 2) break;
}

console.log(result.join('-'));

function outer() {
  console.log(innerVar);
  console.log(typeof innerFunc);
  
  var innerVar = 42;
  
  function innerFunc() {
    return innerVar;
  }
  
  let anotherVar = 100;
  console.log(typeof anotherVar);
}

outer();

console.log(MyClass);
class MyClass {
  constructor() {
    this.value = 42;
  }
}

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

const sum = numbers.reduce((acc, curr) => {
  setTimeout(() => {
    acc += curr;
  }, 0);
  return acc;
}, 0);

console.log(sum);

function Vehicle(wheels) {
  this.wheels = wheels;
}

Vehicle.prototype.getWheels = function() {
  return this.wheels;
};

function Car() {
  Vehicle.call(this, 4);
  this.doors = 4;
}

Car.prototype = Object.create(Vehicle.prototype);
Car.prototype.constructor = Car;

const myCar = new Car();
console.log(myCar.getWheels(), myCar instanceof Vehicle);

const target = { name: 'Maya', age: 25 };
const handler = {
  get(obj, prop) {
    if (prop in obj) {
      return obj[prop];
    }
    return `Property '${prop}' not found`;
  },
  set(obj, prop, value) {
    if (typeof value === 'string') {
      obj[prop] = value.toUpperCase();
    } else {
      obj[prop] = value;
    }
    return true;
  }
};
const proxy = new Proxy(target, handler);
proxy.city = 'tokyo';
console.log(proxy.name);
console.log(proxy.city);
console.log(proxy.country);