您好，我正在尝试让这个程序添加整个循环中累积的所有总成本。但该程序会继续打印最新的成本，而不是所有已“购买”的产品。这是我的代码:`
var Customer_Name, Discount, Product="", Price, Quantity="", Cost ;
var blanket_price = 25;
var lotion_price = 60;
var surfboard_price = 60;
var sunscreen_price = 60;
var Customer_Name = prompt("Welcome to Jersey Shore Inc.! What is your name?","Type Name Here");
alert("Hello "+Customer_Name+", Please look through all available products and services before placing your order.");
do
{
Product= prompt("What product would you like?","Type Product Name Here");
Quantity= prompt("How much of the "+Product+" would you like?","Type Quantity Here");
var Total_Cost;
var SumOrderTotal=0;
if (Product == "blanket")
{
alert("You received a 50% discount! Click okay to see your receipt below.");
Total_Cost= 0.5*(Quantity*blanket_price);
Cost=(Quantity*blanket_price);
Discount = .50*blanket_price;
}
else if (Product == "lotion")
{
alert("You received a 50% discount! Click okay to see your receipt below.");
Total_Cost= 0.5*(Quantity*lotion_price);
Cost=(Quantity*lotion_price);
Discount = .50*lotion_price;
}
else if (Product == "surfboard")
{
alert("You received a 50% discount!Click okay to see your receipt below.");
Total_Cost= 0.5*(Quantity*surfboard_price);
Cost=(Quantity*surfboard_price);
Discount = .50*surfboard_price;
}
else if (Product == "sunscreen")
{
alert("You received a 50% discount! Click okay to see your receipt below.");
Total_Cost= 0.5*(Quantity*sunscreen_price);
Cost=(Quantity*sunscreen_price);
Discount = .50*sunscreen_price;
}
if((Product=="blanket" || Product=="sunscreen" || Product=="lotion" || Product=="surfboard"))
{
document.write("The cost of buying " + Quantity+ " of " + Product + " is $ "+ Cost +". </br>");
document.write("The discount for this purchase is $ "+Total_Cost+". <br/>");
}
else
{
alert("Sorry "+Customer_Name+" you entered an invalid product.(Refer to table for our products) Please Refresh the page to reload and place a new order.");
}
var SumOrderTotal = Total_Cost + SumOrderTotal;
var user_answer=confirm("Would you like to continue purchasing products?");
}
while(user_answer==true);
document.write("Thank you for placing an order with us, " +Customer_Name+". <br/>");
document.write("Your total order cost is $"+ SumOrderTotal+ ". <br/>");
`
最佳答案
将 SumOrderTotal 移到 do...while 之外。
像这样:
var SumOrderTotal=0;
do {
Product = prompt("...");
Quantity = prompt("...");
var Total_Cost;
} while (...) {
...
}
因为每次开始循环时都会初始化为 0(do..while)。
关于Javascript 变量问题，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/15698911/