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JavaScript Object-Oriented JavaScript (2015) Introduction to Methods Finishing the Calculator

Posted by Sharon Kearney
Sharon Kearney
8,662 Points

code challenge

can't get past the beginning. implement subtract method.

var calculator = { sum: 0; add: function (value) { this.sum += value; }, subtract: function (value) { this.sum += value; },

calculator.js 
var calculator = {
  sum: 0,
  add: function(value) {
    this.sum += value;
  },
  subtract: function(value) {
  this. sum += value;
  },
  multiply: function(value) {

  },
  divide: function(value) {

  },
  clear: function() {
    this.sum = 0 ;
  }, 
  equals: function() {
    return this.sum;
  }
}

1 Answer

Jake Lundberg
Jake Lundberg
13,965 Points
Jake Lundberg
Jake Lundberg
13,965 Points

It is because of two things:

First, you have a space between "this." and "sum". You need to be sure and keep these together.

Second, you are trying to add instead of subtract. So your code should look like this: 

this.sum -= value;

Hope this helps!