Question

C#有关循环体和goto

……
BankClient clientX;

a:Console.WriteLine("请输入姓名：");
name = Console.ReadLine();
switch (name)
{
case "张三": clientX = clientA; break;
case "李四": clientX = clientB; break;
case "王五": clientX = clientC; break;
case "赵六": clientX = clientD; break;
default: Console.WriteLine("没有这个用户！"); goto a;
}

Console.WriteLine("请输入密码：");
pw = Console.ReadLine();

if (clientX.getBalance(pw) != -1)
{
Console.WriteLine("您的余额为：" + clientX.getBalance(pw));
}
……

部分程序如上
BankClient是之前写好的类，clientA/B/C/D都是这个类的对象
用循环结构的时候会提示“使用了未赋值的局部变量clientX”报错
求不用goto的解决方案

Answer 1

试试这样:
BankClient clientX = null;

while (null == clientX)
{
Console.WriteLine("请输入姓名：");
name = Console.ReadLine();
switch (name)
{
case "张三": clientX = clientA; break;
case "李四": clientX = clientB; break;
case "王五": clientX = clientC; break;
case "赵六": clientX = clientD; break;
default: Console.WriteLine("没有这个用户！"); break;
}
}

Answer 2

……
BankClient clientX;

bool flag = false;
while(true)
{
Console.WriteLine("请输入姓名：");
name = Console.ReadLine();
switch (name)
{
case "张三": clientX = clientA; break;
case "李四": clientX = clientB; break;
case "王五": clientX = clientC; break;
case "赵六": clientX = clientD; break;
default: Console.WriteLine("没有这个用户！"); flag=true; break;
}
if(flag == false)
break;
}

Console.WriteLine("请输入密码：");
……

Answer 3

把goto a;
换成
Console.WriteLine("请输入姓名：");
name = Console.ReadLine();
然后再把上面的a:去掉就行了