Property Value prototype chain of title issues
1. When the read attribute, automatically to find the prototype chain,
2. set a property value, does not find the prototype chain, if this property is not currently, and added directly set its value attribute.
The method is generally defined to the prototype, the property object itself to the general definition of the constructor.
Instanseof is how to judge
a the instanceof b
if b prototype object display function, an implicit prototype chain in a subject, return true else return false;