Building a cash register number 5


I don't know if I am calling it wrong or doing the function wrong on Void last transaction,
I don't even know What void Means.
"var cashRegister = {
//Dont forget to add your property
add: function(itemCost) { += 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
//Void the last transaction and then add 3 instead
//Show the total bill
console.log('Your bill is ';"


Hey @coder4294967296,

First is first. I don't know if this was in your code, probably not,

but there's a quotation mark behind var cashRegister.

Now, you called the function incorrectly here:

It's structure is supposed to be like this:

cashRegister.scan('______', quantity);

Got it? It's something like that.

Also, just to make things easier:

Instead of doing it like that, you can just use -=, which means to subtract, the total amount from it and to put that as the value of the variable. :smiley:


Thanks, only problem is that it is not working!


Your code? (Edited one, please)


Instead of putting the result of - this.lastTransactionAmount back into this.lastTransactionAmount, you have to update the result of instead.

//Add the voidLastTransaction Method here
voidLastTransaction: function(){ -= this.lastTransactionAmount;


thanks for your help