在构造函数中创建JavaScript原型

Question

What happens in memory when you add to an object's prototype in the constructor? Does it get it recreated every time you make a new object?

For example:

function Foo(){
  Foo.prototype.bar = function() {
    console.log("bar func called");
  }
}    
var x = new Foo();
x.bar();
var y = new Foo();
y.bar();

Answer 1

The "nature" of the code doesn't matter, it's executed every time you call it. This means that yes, every time you call new Foo() the function bar of the prototype is reassigned.

This also means that every Foo object out there get a new bar method, even those that already existed.

Answer 2

每次调用该函数时，放入该函数中的所有代码都会运行，即使该代码分配了原型的属性也是如此。

Answer 3

Yes it does. The creation code will be executed each time you instantiate Foo.