在这种情况下,如何对 C# 使用 do while 循环
本文关键字:使用 do while 循环 这种情况下 | 更新日期: 2023-09-27 18:36:37
static void Main()
{
Console.WriteLine("Please Input the type of coffee you want! Your options are small, medium, or large!");
double coffeeprice = 0;
string coffeechoice = Console.ReadLine();
switch (coffeechoice.ToUpper())
{
case "SMALL":
coffeeprice += 2.00;
break;
case "MEDIUM":
coffeeprice += 4.00;
break;
case "LARGE":
coffeeprice += 6.00;
break;
}
Console.WriteLine("Generating receipt for your {0} order now!", coffeechoice);
}
}
是的,我知道代码写得不好等。我知道有更好的方法可以做到这一点,但我实际上是一个死去的初学者。我想知道的只是,如果我放置一个无效的语句,比如我放一个无效的语句,比如我把 HJFRJKLHRKLKEJS 而不是小、中或大,我会在哪里以及如何在这个语句中放置一个 while 循环或 while 循环。
Whelp我找到了答案!
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Please Input the type of coffee you want! Your options are small, medium, or large!");
double coffeeprice = 0;
string coffeechoice = Console.ReadLine();
do
{
switch (coffeechoice.ToUpper())
{
case "SMALL":
coffeeprice += 2.00;
break;
case "MEDIUM":
coffeeprice += 4.00;
break;
case "LARGE":
coffeeprice += 6.00;
break;
default:
Console.WriteLine("Invalid input please try again!");
coffeechoice = Console.ReadLine();
break;
}
} while (coffeechoice.ToUpper() != "SMALL" && coffeechoice.ToUpper() != "MEDIUM" && coffeechoice.ToUpper() != "LARGE");
Console.WriteLine("Generating receipt for your {0} order now!", coffeechoice);
}
}
事实证明,我所要做的就是将 coffeechoice 声明为 Console.ReadLine(); 再次,这样它就可以断章取义地存在!
你已经回答了你自己的问题,但这是另一种方式。您已经注意到需要修复变量范围。这是您的另一个终止条件。我使用了与价格的匹配,因为您从零开始,并且仅在收到有效输入后设置价格。
//initialize coffeechoice to have it in scope at the end when you need it after the loop
string coffeechoice = "";
double coffeeprice = 0;
do {
Console.WriteLine("Please Input the type of coffee you want! Your options are small, medium, or large!");
coffeechoice = Console.ReadLine();
switch (coffeechoice.ToUpper()) {
case "SMALL":
coffeeprice = 2.00;
break;
case "MEDIUM":
coffeeprice = 4.00;
break;
case "LARGE":
coffeeprice = 6.00;
break;
}
} while (coffeeprice == 0); //price not set, no valid input accepted
Console.WriteLine("Generating receipt for your {0} order now!", coffeechoice);
Console.WriteLine("You paid {0}", coffeeprice);
把它放在你的主方法中,试一试!
我认为你不需要在这里看一会儿:您可以定义一个案例"默认",并在输入不是这 3 种情况中的任何一种的情况下再次请求输入。要定义默认大小写,您可以执行以下操作:
default:
Console.WriteLine("Please Input the type of coffee you want! Your options are small, medium, or large!");
string coffeechoice = Console.ReadLine();
break;
您可以使用一个变量来指示输入是否有效(如下所示)。虽然可以检查咖啡价格 == 0,但我不喜欢这种方法,因为它没有明确说明输入,并且定价的变化可能也需要更改此逻辑。
另外,我不确定为什么您只想在输入无效时才循环,因为这会使咖啡价格 += 变得不必要。
bool isInputValid = false;
double coffeeprice = 0;
do
{
Console.WriteLine("Please Input the type of coffee you want! Your options are small, medium, or large!");
string coffeechoice = Console.ReadLine();
isInputValid = true;
switch (coffeechoice.ToUpper())
{
case "SMALL":
coffeeprice += 2.00;
break;
case "MEDIUM":
coffeeprice += 4.00;
break;
case "LARGE":
coffeeprice += 6.00;
break;
default:
isInputValid = false;
break;
}
}while (isInputValid == false);
Console.WriteLine("Generating receipt for your {0} order now!", coffeechoice);
你的代码是这样的
更新:
double coffeprice=0;
do
{
Console.WriteLine("Enter you choice:");
string coffeechoice = Console.ReadLine();
switch (coffeechoice.ToUpper())
{
case "SMALL":
coffeeprice += 2.00;
break;
case "MEDIUM":
coffeeprice += 4.00;
break;
case "LARGE":
coffeeprice += 6.00;
break;
}
}
while(coffeprice>0);