new vs object create giving different results OO javascript

Question

I'm working with a data object lit, then trying to create a new object that changes properties in the data property just for that instance, here's some test code from jsbin

data = {
  innerData : 1 
}

-------------

'This works :-)'

construct = function(d){
  this.data = Object.create(d);
};

construct.prototype.c = function(n){
  this.data.innerData  =  n;
};

construct.prototype.d = function(){
   console.log(this.data.innerData)
};

--------------

'This does not :-{'

construct = {
  data : Object.create(data),
  changeData : function(n){
    this.data.innerData  =  n;
  },
  showData:function(){
    console.log(this.data.innerData)
  }
}

--------------

newInst = Object.create(construct);
newInst.changeData(5);
newInst.showData();

newInst2 = Object.create(construct);
newInst2showData();

when I run it using the constructor/prototype functions it works and the console outputs 5,2

when I run it using the object literal the console outputs 5,5 I guess when I create the first instance it changes the actual data object and not the data property of the instance of the construct object.

If someone could explain in depth why this happens that would be much help as I've not been working with OOJS for that long

UPDATE:

so I had a little go at merging what I found useful from the answers and I've come up with this....

data = {
  innerData : 1 
}

function construct(d){
  return {
    data : Object.create(d),
    changeData : function(n){
      this.data.innerData  =  n;
    },
    showData : function(){
      console.log(this.data.innerData)
    }
  }
}

build = function(){
 return(new construct(data));
}

newInst = build();
newInst.changeData(5);
newInst.showData();

newInst2 = build();
newInst2.showData();

Answer 1

In your second example, there is only ever one data object. That object lives inside construct and is available to all the subsequent objects on the prototype chain.

In your first example, you make a new data object every time a new instance is created. So each object gets its own copy of data.

Try this, for the first example:

console.log(newInst.data === newInst2.data); // should be false

and for the second example:

console.log(newInst.data === newInst2.data); // should be true