Why do I recieve [object Object] answer in my CALCULATOR?

Question

I just finished Object Oriented Java Script and trying to put it all together;
What should I change?
this is my code (it is from one exercise): 
```
JavaScript
var calculator = {
  sum: 5,
  add: function(value) {
    this.sum += value;
  },
  subtract: function(value) {
    this.sum -= value;
  },
  multiply: function(value) {
    this.sum *= value;
  },
  divide: function(value) {
    this.sum /= value;
  },
  clear: function() {
    this.sum = 0;
  }, 
  equals: function() {
    return this.sum;
  }
}
calculator.add(5);
calculator.equals();
var display = calculator
alert(calculator); 
```

zainsra7 · Accepted Answer

Hi, 
Let's write the code again and see why you're getting that message and what's the solution:
javascript
var calculator = {
  sum: 5,
  add: function(value) {
    this.sum += value;
  },
  subtract: function(value) {
    this.sum -= value;
  },
  multiply: function(value) {
    this.sum *= value;
  },
  divide: function(value) {
    this.sum /= value;
  },
  clear: function() {
    this.sum = 0;
  }, 
  equals: function() {
    return this.sum;
  }
}

Above code is simply a calculator object with a bunch of useful methods.
Now let's analyze your code :
javascript
calculator.add(5); //This adds 5 to the sum , so after this sum will be 10.
calculator.equals(); //This returns the sum, but you didn't catch it in a variable
var display = calculator 
alert(calculator);  //calculator is an object and with this line you're going to see "[Object object]" in alert dialog box

Let's see the solution:
javascript
calculator.add(5); //This adds 5 to the sum , so after this sum will be 10.
var display = calculator.equals(); //equals() method returns sum "10"and we catch it in a variable called display.
alert(display);  //This will now show value of display variable "10" in an alert dialog box.

I hope it answers your question, Happy Coding !
Zain

Mikhailo Rozumovskyy · Answer

ooh,  I see, I understand it now. My bad! Thank You!

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Mikhailo Rozumovskyy

Mikhailo Rozumovskyy

Why do I recieve [object Object] answer in my CALCULATOR?

2 Answers

zainsra7

zainsra7

Mikhailo Rozumovskyy

Mikhailo Rozumovskyy