Bleep bleep


#1

Here is my code. i get the wrong value and "Oops, try again.false"
what is the problem?
thanks

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 -= 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 ('eggs',3);

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


#2

There are two problems, here,


#3

@mtf I still do not see what the problem is


#4

We never use whitespace in a function call...

cashRegister.voidLastTransaction();

and we are expected to void 4 chocolate and scan 3, instead.

cashRegister.scan('chocolate', 3);

#5

@mtf thank you soo much! :smile:


#6
//Could you check my code, did follow all of the instructions that you mentioned 

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 -= 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('chocolate',4);
cashRegister.scan("chocolate", 3);
//Show the total bill
console.log('Your bill is '+cashRegister.total);

but still error


#7

The variable needs to be in object context,

    this.total -= this.lastTransactionAmount;