Why is it necessary to set the prototype constructor?

Question

In the section about inheritance in the MDN article Introduction to Object Oriented Javascript, I noticed they set the prototype.constructor:

// correct the          


        

Answer 1

Here's one example from MDN which I found very helpful to understand its uses.

In JavaScript, we have async functions which returns AsyncFunction object. AsyncFunction is not a global object but one may retrieve it by using constructor property and utilize it.

function resolveAfter2Seconds(x) {
  return new Promise(resolve => {
    setTimeout(() => {
      resolve(x);
    }, 2000);
  });
}

// AsyncFunction constructor
var AsyncFunction = Object.getPrototypeOf(async function(){}).constructor

var a = new AsyncFunction('a', 
                          'b', 
                          'return await resolveAfter2Seconds(a) + await resolveAfter2Seconds(b);');

a(10, 20).then(v => {
  console.log(v); // prints 30 after 4 seconds
});