Output: changing a prototype property after creating an instance, then replacing the prototype object

1function Dog() {}
2Dog.prototype.sound = 'woof';
3const d1 = new Dog();
4 
5Dog.prototype.sound = 'bark';
6console.log(d1.sound);
7 
8Dog.prototype = { sound: 'meow' };
9const d2 = new Dog();
10console.log(d1.sound, d2.sound);
11console.log(d1 instanceof Dog, d2 instanceof Dog);