CODEWITHSUNDEEP
javascript
strangfeld
strangfeld

Reputation: 1067

Javascript Reference Confusion

The class gets instantiated and stored in a variable. The reference of the variable is used to change 'prop' to 'change'. The reference is passed and stored in another variable and logged out. Aaaaaaaaaannnndddd I don't get it.

function ctrl () {

  function Klasse () {
      this.prop = 'prop';
  }

  var _klasse = new Klasse();

  return {
      get: function () {
          console.log('get', _klasse);
          return _klasse
      },
      change: function () {
          _klasse.prop = 'changed';
          console.log('change', _klasse);
      },
      reset : function () {
          _klasse = new Klasse();            
      }
  }
}

ctrl().change();
var _klasseReferenz = ctrl().get();

// Why is _klasseReferenz.prop !== 'changed' ????
console.log('referenz ', _klasseReferenz);

Fiddle: http://jsfiddle.net/Lfg85x96/1/

Upvotes: 0

Views: 45

Answers (4)

h0tfus3
h0tfus3

Reputation: 592

You are creating to references of the ctrl function. Instead of ctrl().change() and ctrl().get() just assign a new ctrl instance to a variable

var _ctrl = new ctrl();
ctrl.change();
ctrl.get();

Upvotes: 0

KanhuP2012
KanhuP2012

Reputation: 407

ctrl().change(); --> you are just calling function seperately (not saving reference call)

var _klasseReferenz = ctrl().get(); --> In this like you are creating an object.

// Why is _klasseReferenz.prop !== 'changed' ???? console.log('referenz ', _klasseReferenz);

In first line you are only calling function and there is no reference, from the second line onward you have created an object and start refrencing it.

Use below line of code to understand

var ctl = new ctrl();
ctl.change();
console.log('NowRefrenceWorking ', ctl.get());

Upvotes: 0

Scimonster
Scimonster

Reputation: 33399

Each time you call ctrl() you create a new instance of _klass local to that closure. You need to save the reference call, and call get and update on that.

var reference = ctrl();
reference.change();
var _klasseReferenz = reference.get();

Upvotes: 0

Max Brodin
Max Brodin

Reputation: 3938

Because every time you call ctrl it will create new Klasse instance. You should change this to:

var ctrlInstance = new ctrl();
ctrlInstance.change();
var _klasseReferenz = ctrlInstance.get();

console.log('referenz ', _klasseReferenz);

See fiddle

Upvotes: 1

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