Performance in Javascript objects

Question

By which means are obtained the best performance of Javascript objects.

var Objeto = { 
    propriedade:'valorPropriedade',
    init:function() {
       //Inicia Objetos  
    }
}
var obj = Objeto.init();

or:

function Objeto() {
   this.propriedade = 'valorPropriedade';
   this.init = function(){
        //Função para iniciar o Objeto
   }
}

var obj = new Objeto();
obj.init();

Answer 1

The first option for sure. When you create a constructor function and create an object through new, you are creating a chain of prototypes. That is, every object of the type Objeto owns a property [[prototype]] (is not visible from Javascript code, only indirectly via Object.getPrototypeOf(obj)) which, in this case, is a Object common (because you have not explicitly assigned the Objeto.prototype).

Objeto --> Object --> Object.prototype --> null

When you don’t have a class Objeto, only a literal, its object is of the simple type Object, so that long string does not exist.

Object --> Object.prototype --> null

This reduces all operations that Javascript has to do on its object in 1 level. In practice, it shouldn’t make much difference, but if you want to squeeze every CPU cycle (I think it’s silly, in my opinion, but it’s your choice) then this option will be faster. Note: in the test that Linkei above the performance is extremely different, but it is because the code does nothing useful. As the program grows, this difference must become smaller, or even negligible.

Updating: as pointed out by @bfavaretto, the difference in performance is mostly the extra call from the constructor. If your code will do this frequently (create new objects) then the solution that does not use constructor should be faster. However, little can be said about the use of objects created in one way or another (at least not from this test).