How JavaScript works behind the prototype

Let's start with a function.functionfn1 (name, age) { This. Name =name;  This. Age =Age ;  This. Say =function() {alert (' My name: ' + This. Name + ' and age: ' + This. Age); }}fn1.prototype.test=function() {alert (' Test ');}varF1 =NewFN1 (' JM ', 20); F1.say (); //pop-up my name JM and agef1.test ();//pop-up testWhat's going on here?

Something of its own. We need to know that each function has a reserved property prototype it returns an object

This object can be written or read.

Each function new object has an implicit property (__proto_ = Fn1.prototype) that points to the prototype of the constructor!

The following diagram illustrates the principle of prototype, (there are some references on the Internet):

How JavaScript works behind the prototype