Bleep Bleep: Error 'cashRegister not a function'


#1


Hello,

I have an error on the Building a Cash Register / Bleep Bleep exercise.


https://www.codecademy.com/courses/close-the-super-makert/0/5?curriculum_id=506324b3a7dffd00020bf661

TypeError: cashRegister.scan is not a function


var cashRegister = {
    total:0,
    lastTransactionAmount:0,
    //Dont forget to add your property
    add: function(itemCost) {
        this.total +=  itemCost;
        this.lastTransactionAmount = this.total +  itemCost;
    },
    scan: function(item,quantity) {
        switch (item) {
        case "eggs": this.add(0.98 * quantity); break;
        case "milk": this.add(1.23 * quantity); break;
        case "magazine": this.add(4.99 * quantity); break;
        case "chocolate": this.add(0.45 * quantity); break;
        }
        return true;
    },
    //Add the voidLastTransaction Method here
    voidLastTransaction: function() {
        this.scan -= this.lastTransactionAmount;
    }
};

cashRegister.scan('eggs',1);
cashRegister.scan('milk',1);
cashRegister.scan('magazine',1);
cashRegister.scan('chocolate',4);

//Void the last transaction and then add 3 instead
cashRegister.voidLastTransaction();
cashRegister.scan('chocolate',3);

//Show the total bill
console.log('Your bill is '+cashRegister.total);


#2

Hi there,

The error is on line 20.

voidLastTransaction: function() {
         this.scan -= this.lastTransactionAmount;
}

this.scan should read this.total because when we void the last transaction we want to take away whatever value is stored in lastTransactionAmount from the total currently scanned.

Hope that helps,


#3

And also your "this.lastTransactionAmount = thi.total + itemCost" should change to"this.lastTransactionAmount = itemCost" Because we only want to subtract the amount of last time we scanned.


#4

Hello both,

Thanks a lot for the help. Unfortunately, I still have the same error. Any idea why?


#5

this.lastTransactionAmount = this.total + itemCost; -> this.lastTransactionAmount = itemCost;


#6

This is your code fixed.

var cashRegister = {
    total:0,
    lastTransactionAmount: 0,
    
    //Dont forget to add your property
    add: function(itemCost) {
        this.total +=  itemCost;
        this.lastTransactionAmount = itemCost;
    },
    
    
    scan: function(item,quantity) {
        switch (item) {
        case "eggs": this.add(0.98 * quantity); break;
        case "milk": this.add(1.23 * quantity); break;
        case "magazine": this.add(4.99 * quantity); break;
        case "chocolate": this.add(0.45 * quantity); break;
        }
        return true;
    },
    //Add the voidLastTransaction Method here
    
    voidLastTransaction: function () {
        this.total -= this.lastTransactionAmount;
    },
    
};

cashRegister.scan('eggs',1);
cashRegister.scan('milk',1);
cashRegister.scan('magazine',1);
cashRegister.scan('chocolate',4);

//Void the last transaction and then add 3 instead
cashRegister.voidLastTransaction();
cashRegister.scan('chocolate',3);


//Show the total bill
console.log('Your bill is '+cashRegister.total);

#7

Hi, since this is the last parameter, why do I need to use comma ?


#8

You are right. It actually is not needed!


#9

Thanks for comfirmation :wink:

This is a codecademy bug propably.
In next exercise we need to add something so the comma in this exercise is propably required because of that.


#10

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