Advanced OOP

Preview — 3 of 19 questions

What will the following code output?

javascript

const animal = {
  type: 'Animal',
  describe() {
    return `I am a ${this.type}`;
  }
};

const dog = Object.create(animal);
dog.type = 'Dog';
console.log(dog.describe());

A"I am a Animal"

B"I am a Dog"

Cundefined

DTypeError

What will the following code output?

javascript

const obj = {};
Object.defineProperty(obj, 'secret', {
  value: 42,
  enumerable: false,
});

console.log(obj.secret);
console.log(Object.keys(obj).includes('secret'));

A42 and true

Bundefined and false

C42 and false

DTypeError

What will the following code output?

javascript

const handler = {
  get(target, prop) {
    return prop in target ? target[prop] : `Property ${prop} not found`;
  }
};

const user = new Proxy({ name: 'Alice' }, handler);
console.log(user.name);
console.log(user.age);

A"Alice" and undefined

B"Alice" and "Property age not found"

C"Alice" and null

DTypeError

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