May I know where the object name printed by console.log in chrome points?

  node.js, question

Js code:

function A(x){
 this.x = x ;
 bracket
 
 function B(y) {
 this.y = y;
 bracket
 
 B.prototype = new A(1);
 
 function C(z) {
 this.z = z;
 bracket
 var b = new B(2);
 C.prototype = new B(2);
 
 console.log(b);
 console.log(C.prototype);
 
 console.log(b instanceof A);
 console.log(C.prototype instanceof A);
 console.log(b.constructor);
 console.log(C.prototype.constructor);

Print results:

clipboard.png

As shown in the figure: b and c prototype are instantiating objects of constructor b why when printing these two objects, the first letter of the result displayed by b is b, while the first letter displayed by c prototype is a, and the results of the two through instantiation of and constructor are consistent, please help the great gods to solve the puzzle, thank you very much.

Please see javascript’s explanation of the prototype chain for details.Inheritance and Prototype Chain
instanceof