[solved] 5/7 Help me


#1

Please, i don't understand on this session :relieved:

my code

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.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();

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


#2

All of your codes are looking fine except you missing this two part:
First in your add method, you have to add

this.lastTransactionAmount = itemCost

to keep track of your latest transaction.
Second, add 3 of your last transaction (instead of 4 chocolate),

cashRegister.scan('chocolate',3);

#3

var cashRegister = {
total: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.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);