Cant we copy prototype by Song.prototype = Media.prototype

Hi lokesh cherukuri,

We want Song's prototype object to inherit functionality from Media's prototype object. In other words, we want any object that Song produces (using the new keyword) to be able to use methods on both Song.prototype and Media.prototype.

However, we don't want to put any methods that should belong to Song.prototype on Media.prototype, or write over any of Media.prototype's methods when setting up Song.prototype.

Setting

Song.prototype = Media.prototype

means that both would share the exact same object, meaning that any changes made to Song.prototype would show up on Media.prototype.

By setting

Song.prototype = Object.create(Media.prototype)

we get a fresh, blank object that still inherits from Media.prototype. So now changes made to Song.prototype won't pollute Media.prototype, but any changes made to Media.prototype can be accessed by song instances.

Does that make sense?