Beep Beep: Almost there but need help


#1

This seems to be right, I keep receiving error messages. What's wrong below?

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.lastTranactionAmount;
}
};

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

@lake529,

Have a close look at

lastTranactionAmount


#3

Bravo. Thank you very much.