在Javascript中对父属性执行`delete`

Question

I was wondering what happens when you (possibly accidentally) delete a parent property (ie one from the prototype chain). Will delete just fail or will it remove the property from the prototype? What I mean is something like:

var pro = { "a": 1 };
var obj = Object.create(pro);
delete obj["a"]; // <- what will happen here?
delete obj.a; // <- or here? any difference to the one above

Answer 1

delete obj[a] will return an error; delete obj.a will return true, and nothing will happens

if you change obj.a = 2; and then delete obj.a, it will reset the value to the initial one (obj.a == 1);