#5/7 Oops try again, false; what am i doing wrong?


#1

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


#2

Hey @coreace66655! Dont forget to update your lastTransaction amount in your add function..

Your add function looks like this

Just add the transaction amount by adding this after the this.total+=itemCost:

So like this:

add: function(itemCost) {
this.total += itemCost;
this.lastTransactionAmount = itemCost;
},
So you can update your transaction amount. Hope this helped!! If it didnt please reply saying so


#3

Thank u so much. It worked. :smiley:


#4

My code doesn't work, and I can't find out why.

var cashRegister = {
    total:0,
    //Dont forget to add your property
    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-=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);

It seems to be the same as the code above, but it gives an error "lastTransactionAmount is not defined"


#5

Hey here is your mistake,

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

You haven't put 'this' before lastTransactionAmount

Do this :smile:

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


#6

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);

getting an unexpected token syntax error, can anyone help me please!


#7

Hello , you have small mistake:

you don't just have closing bracket of this function

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

So, do this

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

Hope this helps


#8

Big thanks! I would've never seen that.