--description--

Since numLegs will probably have the same value for all instances of Bird, you essentially have a duplicated variable numLegs inside each Bird instance.

This may not be an issue when there are only two instances, but imagine if there are millions of instances. That would be a lot of duplicated variables.

A better way is to use the prototype of Bird. Properties in the prototype are shared among ALL instances of Bird. Here's how to add numLegs to the Bird prototype:

Bird.prototype.numLegs = 2;

Now all instances of Bird have the numLegs property.

console.log(duck.numLegs);
console.log(canary.numLegs);

Since all instances automatically have the properties on the prototype, think of a prototype as a "recipe" for creating objects. Note that the prototype for duck and canary is part of the Bird constructor as Bird.prototype.

--instructions--

Add a numLegs property to the prototype of Dog

--hints--

beagle should have a numLegs property.

assert(beagle.numLegs !== undefined);

beagle.numLegs should be a number.

assert(typeof beagle.numLegs === 'number');

numLegs should be a prototype property not an own property.

assert(beagle.hasOwnProperty('numLegs') === false);

--seed--

--seed-contents--

function Dog(name) {
  this.name = name;
}



// Only change code above this line
let beagle = new Dog("Snoopy");

--solutions--

function Dog (name) {
  this.name = name;
}
Dog.prototype.numLegs = 4;
let beagle = new Dog("Snoopy");