Prototype chain

_proto_Used as a bridge between different objects to point to the prototype object that created its constructor

  • Each object _proto_ refers to the prototype object of its constructor

person1._proto_ === Person.prototype

  • A constructor is a Function object generated through the Function constructor

Person._proto_ === Function.prototype

  • The prototype Object itself is an ordinary Object, and the constructors of ordinary objects are all Objects

Person.prototype._proto_ === Object.prototype

  • All constructors are Function objects, and Function objects are generated by Function constructs

Object._proto_ === Function.prototype

  • Prototype objects of Object also have a _proto_ attribute pointing to NULL, which is the top of the prototype chain

Object.prototype._proto_ === null