No methods in constructor, no properties in prototype

gistfile1.js

var Class = function () {
    this.a = 'abc';
    this.b = 666;
    this.c = function () {
        return 3 * 3;
    };
}

Class.prototype.d = function () {
    return 2 + 2;
};

Class.prototype.e = [];

var obj1 = new Class;

obj1.e.push(1);
console.log(obj1.e) // [1]

for (var i in obj1) 
    if (obj1.hasOwnProperty(i))
        console.log(i, typeof obj1[i]) // a string, b number, c function


var obj2 = new Class;

obj2.e.push(1);
console.log(obj2.e) // [1, 1]