Advanced JavaScript: Event Loop & Engine Architecture Practice Quiz & Assessment – TutorialsHub

1. In what order will the console logs execute in this JavaScript snippet?

console.log('1');

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

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

console.log('4');

A 1, 2, 3, 4 B 1, 4, 3, 2 C 1, 3, 4, 2 D 1, 4, 2, 3

2. Why does WeakMap prevent memory leaks compared to standard Map in JavaScript?

const wm = new WeakMap();

let user = { name: "Alex" };

wm.set(user, "meta_data");

user = null;

A WeakMap deletes its values every 60 seconds automatically B Keys are weakly held, allowing garbage collection when no other references exist C WeakMap converts all keys to lightweight primitive strings D WeakMap encrypts memory values in the heap

3. Which JavaScript Proxy trap intercepts property access such as obj.property?

const p = new Proxy(target, {

  ______(target, prop, receiver) {

    return Reflect.get(...arguments);

  }

});

A read B get C access D retrieve

4. What is the true difference between Object.freeze() and Object.seal()?

A They are identical aliases in ECMAScript B freeze() makes properties read-only, whereas seal() allows modifying existing writable values C seal() encrypts the object structure while freeze() does not D freeze() is async while seal() is synchronous

5. What JavaScript method is called by a Generator function to pause and resume execution?

function* idGen() {

  let id = 1;

  while(true) {

    ______ id++;

  }

}

A return B yield C pause D await

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