const user = { name: 'Sarah', age: 28 };
const greeting = 'Hello';
const template = `${greeting}, ${user.name}! You are ${user.age} years old.`;

function createMessage(strings, ...values) {
  return strings.reduce((result, string, i) => {
    return result + string + (values[i] ? `[${values[i]}]` : '');
  }, '');
}

const tagged = createMessage`Welcome ${user.name}, age: ${user.age}!`;
console.log(template);
console.log(tagged);

const wm = new WeakMap();
const obj1 = { name: 'first' };
const obj2 = { name: 'second' };

wm.set(obj1, 'value1');
wm.set(obj2, 'value2');

const keys = [];
for (let key of wm) {
  keys.push(key);
}

console.log(keys.length);
console.log(wm.has(obj1));
console.log(wm.get(obj2));

const target = { name: 'Sarah', age: 25 };
const handler = {
  get(obj, prop) {
    if (prop === 'info') {
      return `${obj.name} is ${obj.age}`;
    }
    return Reflect.get(obj, prop);
  },
  has(obj, prop) {
    return prop !== 'age' && Reflect.has(obj, prop);
  }
};
const proxy = new Proxy(target, handler);
console.log(proxy.info);
console.log('age' in proxy);
console.log('name' in proxy);

console.log('1');

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

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

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

setTimeout(() => {
  console.log('5');
  Promise.resolve().then(() => console.log('6'));
}, 0);

console.log('7');