Bleep Bleep! Oops, try again. false


#1

What is the problem here?

var cashRegister = {
    total:0,
    lastTransactionAmount: 0,
    
    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);

Bleep Bleep! "Your bill is NaN"
#2

check out your method at the bottom it is missing parantheses :slight_smile:


#3

Your lastTransactionAmount should be your PREVIOUS itemCost, not SUBTRACTING the itemCost.


It should look like this:
this.lastTransactionAmount = itemCost;