console.log(1);

setTimeout(() => {
  console.log(2);
}, 100);

setTimeout(() => {
  console.log(3);
}, 0);

Promise.resolve().then(() => {
  console.log(4);
}).then(() => {
  console.log(5);
});

console.log(6);

console.log('1');

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

Promise.resolve().then(() => console.log('3'));

queueMicrotask(() => console.log('4'));

setTimeout(() => console.log('5'), 0);

Promise.resolve().then(() => {
  console.log('6');
  return Promise.resolve();
}).then(() => console.log('7'));

console.log('8');

console.log('Start');

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

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

console.log('End');

const secret = 'hidden';
function revealSecret() {
  const secret = 'revealed';
  const obj = { secret: 'object secret' };
  with (obj) {
    return () => secret;
  }
}

const mySecret = revealSecret()();
console.log(mySecret);

class CustomError extends Error {
  constructor(message) {
    super(message);
    this.name = 'CustomError';
  }
}

try {
  try {
    throw new CustomError('inner error');
  } catch (e) {
    console.log(e.name);
    throw new Error('outer error');
  }
} catch (e) {
  console.log(e.message);
  console.log(e instanceof CustomError);
}

const original = {
  name: 'Sarah',
  scores: [85, 92, 78],
  details: {
    age: 25,
    city: 'Portland'
  }
};

const copy1 = { ...original };
const copy2 = JSON.parse(JSON.stringify(original));

copy1.name = 'Emma';
copy1.scores.push(95);
copy1.details.age = 30;

console.log(original.name, original.scores.length, original.details.age);

function Animal() {}

function Dog() {}

Dog.prototype = Object.create(Animal.prototype);

const rover = new Dog();

console.log(rover.constructor === Animal);

const clothes = [ 'jacket', 't-shirt' ];
clothes.length = 0;
console.log(clothes[0]);

const obj = {};
obj.length = 5;
console.log(obj.length);

console.log(typeof typeof undefined);

console.log(NaN === NaN);

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

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

console.log(sum);

function createCounter() {
  let count = 0;
  return {
    increment: () => ++count,
    decrement: () => --count,
    getValue: () => count
  };
}

const counter1 = createCounter();
const counter2 = createCounter();
counter1.increment();
counter1.increment();
counter2.increment();
console.log(counter1.getValue() + counter2.getValue());

const original = {
  name: 'Emma',
  skills: ['JavaScript', 'Python'],
  config: { theme: 'dark', notifications: true }
};

const copy1 = { ...original };
const copy2 = JSON.parse(JSON.stringify(original));
const copy3 = Object.assign({}, original);

copy1.name = 'Sarah';
copy1.skills.push('React');
copy1.config.theme = 'light';

console.log(original.name);
console.log(original.skills.length);
console.log(original.config.theme);

const obj = { a: 1, b: 2, c: 3 };
const result = Object.values(obj).reduce((acc, curr) => acc * curr, 1);
console.log(result);

const obj = {
  name: 'Sarah',
  regularMethod: function() {
    return () => {
      console.log(this.name);
    };
  },
  arrowMethod: () => {
    return () => {
      console.log(this.name);
    };
  }
};

const regular = obj.regularMethod();
const arrow = obj.arrowMethod();
regular();
arrow();

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

console.log('1');
setTimeout(() => console.log('2'), 0);
Promise.resolve().then(() => console.log('3'));
setTimeout(() => console.log('4'), 0);
console.log('5');
Promise.resolve().then(() => {
  console.log('6');
  return Promise.resolve();
}).then(() => console.log('7'));
queueMicrotask(() => console.log('8'));
console.log('9');

class EventManager {
  constructor() {
    this.listeners = new Map();
  }
  
  addListener(event, callback) {
    if (!this.listeners.has(event)) {
      this.listeners.set(event, new Set());
    }
    this.listeners.get(event).add(callback);
  }
}

const manager = new EventManager();
const obj = { name: 'Component' };
manager.addListener('click', () => console.log(obj.name));
obj = null;
console.log(manager.listeners.get('click').size);

const step1 = multiply(2);
const step2 = step1(3);
const result1 = step2(4);

const result2 = multiply(2)(3)(4);

const partialMultiply = multiply(5);
const result3 = partialMultiply(2)(3);

const doubler = multiply(2)(1);
const result4 = doubler(7);

console.log(result1, result2, result3, result4);