Let's summarize the most important topics you have learned in this chapter:
All functions have a property called
prototype. Initially, it contains an empty object-an object without any own properties.You can add properties and methods to the
prototypeobject. You can even replace it completely with an object of your choice.When you create an object using a function as a constructor (with
new), the object gets a secret link pointing to the prototype of the constructor and can access the prototype's properties.An object's own properties take precedence over a prototype's properties with the same name.
Use the
hasOwnProperty()method to differentiate between an object's own properties andprototypeproperties.There is a prototype chain. When you execute
foo.bar, and if yourfooobject doesn't have a property calledbar, the JavaScript interpreter looks for abarproperty in the prototype. If none is found, it keeps searching in the prototype's prototype, then the prototype of the prototype...