5. Bleep Bleep



I can't move on to the next part since I am so lost to what's happening right now, could anyone please explain the code to me?(It's the right code but I'm just confused about everything!)

var cashRegister = {
    lastTransaction: 0,
    //Dont forget to add your property
    add: function(itemCost) {
        this.total +=  itemCost;
        this.lastTransaction = 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.lastTransaction;


//Void the last transaction and then add 3 instead

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


What don't you understand. :slight_smile:


The code that I included and what I'm learning here?


What this new method does is when called after a few instances of the cashRegister have already been created it deletes all of them and now the cashRegister will be empty until new items are scanned. :grin:

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


This was actually one of my favorite units because it gives you a basic skeleton of how a cahsRegister works in a supermarket and with this knowledge you can go and create even your own JS cashRegister that is much more advanced than this one. :slight_smile:


So it kind of like resets the cashRegister total to zero?


Yes, meaning all transactions done up to that point will be made void.


Quick Question, what does void mean? I can't remember and why did the new method called voidLastTransaction, and not just var lastTransaction?


The name of the method can be anything but it is called that for better understanding of what your code is doing,

void : completely empty.


Oh Thank you for the perfect explanation! Appreciate it!


You're welcome :slight_smile:


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