function A(){this.name = "hellow"}
function B(){}
B.prototype = new A();

B.prototype.constructor = A  //true

//这里强调的是 继承了之后 要记得设置回去

B.prototype.constructor = B;

//这里继承成功之后

b.constructor = B.prototype.constructor //true

关于js对象定义理解小记01