c# - 从 if/else 语句中获取值？

Question

如果我有一系列像这样的 if/else 语句，我想在其中获取特定值，那么我将如何在等式之外访问该值？我让一切都通过命令提示符，没有任何其他类。

if (shippingInput == 1)
{
    double shippingAmount = shippingDetails * 3;
}
else if (shippingInput == 2)
{
    double shippingAmount = shippingDetails * 4;
}
else
{
    double shippingAmount = shippingDetails * 5.5;
}

在我的代码末尾，我有

double shippingCost = shippingAmount + surcharge;

但它表示名称“shippingAmount”和“surcharge”在当前上下文中不存在。

感谢您的帮助!我还不能标记答案，但在 if/else 括号外声明语句并从每个括号中删除 double 后，它工作得很好。

Answer 1

您每次都在创建新变量。像这样声明一次:

double shippingAmount;

if (shippingInput == 1)
{
    shippingAmount = shippingDetails * 3;
}
else if (shippingInput == 2)
{
    shippingAmount = shippingDetails * 4;
}
else
{
    shippingAmount = shippingDetails * 5.5;
}