function processConfig(config) {
  const settings = {
    timeout: config.timeout ?? 1000,
    retries: config.retries ?? 3,
    logging: config.logging ?? false,
    debug: config.debug || true
  };
  
  return settings;
}

const userConfig = {
  timeout: 0,
  retries: null,
  logging: false,
  debug: false
};

console.log(processConfig(userConfig));

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);

async function foo() {
  console.log('Start');
  await Promise.resolve().then(() => {
    console.log('Inside Promise');
  });
  console.log('End');
}

foo();
console.log('Outside');

let x = 5;
let result = typeof (x + "10");

console.log(result);

const obj = { name: 'Alice', age: 30 };  
const handler = {
  get(target, prop) {
    return prop in target ? target[prop] : `Property '${prop}' doesn't exist`;
  }
};

const proxy = new Proxy(obj, handler);

const descriptors = Object.getOwnPropertyDescriptors(obj);
Reflect.defineProperty(obj, 'city', {
  value: 'New York',
  enumerable: false
});

console.log(proxy.city, proxy.country);

const numbers = [0,0,0];

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

console.log(i, result);

const array = [1, 2, 3];
array[-1] = 0;

console.log(array.length);