結賬軟體的雛形

var cashRegister = { total: 0, //insert the add method here add: function(itemCost){ this.total += itemCost; }, scan: function (item) { switch (item) { case "eggs": this.add(0.98); break; case "milk": this.add(1.23); break; //Add other 2 items here case 'magazine': this.add(4.99); break; case 'chocolate': this.add(0.45); break; } return true; } }; //Scan 2 eggs and 3 magazines cashRegister.scan('eggs'); cashRegister.scan('eggs'); cashRegister.scan('magazine'); cashRegister.scan('magazine'); cashRegister.scan('magazine'); //Show the total bill console.log('Your bill is '+cashRegister.total); //完整板 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(lastTransactionAmount){ 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);