Question

我正在编写一个程序，允许用户使用switch语句从菜单中选择项目，但是当选择多个项目时，我会得到一个例外。我目前的代码如下。

    System.out.println("Transaction 1");
    System.out.println();
    System.out.println("Menu"); 
    System.out.println();
    System.out.println("(1) Hamburger           $1.99\n(2) Cheeseburger        $2.29\n(3) Chicken Wrap        $3.39\n(4) Chicken Nuggets     $2.29\n(5) Lrg French Fries    $2.49\n(6) Sml French Fries    $1.79\n(7) Bottled Water       $2.19\n(8) Lrg Soda            $1.89\n(9) Sml Soda            $1.49");

    System.out.print("\nPlease type the numbers that correspond to the food you would like to order separated by commas: ");
    toneorder = userInput.nextInt();
    switch (toneorder) {
        case 1: 
            tonefood = "Hamburger";
            break;
        case 2: 
            tonefood = "Cheeseburger";
            break;
        case 3: 
            tonefood = "Chicken Wrap";
            break;
        case 4: 
            tonefood = "Chicken Nuggets";
            break;
        case 5: 
            tonefood = "Lrg French Fries";
            break;
        case 6: 
            tonefood = "Sml French Fries";
            break;
        case 7: 
            tonefood = "Bottled Water";
            break;
        case 8: 
            tonefood = "Lrg Soda";
            break;
        case 9: 
            tonefood = "Sml Soda";
            break;
    }

Answer 1

你需要将整个事情从获取输入，直到switch语句的结尾，抛到循环中。

System.out.print("\nPlease type the numbers that correspond to the food you would like to order separated by spaces: ");

do{
    toneorder = userInput.nextInt();
    switch (toneorder) {
case 1: tonefood = "Hamburger";
    break;
case 2: tonefood = "Cheeseburger";
    break;
case 3: tonefood = "Chicken Wrap";
    break;
case 4: tonefood = "Chicken Nuggets";
    break;
case 5: tonefood = "Lrg French Fries";
    break;
case 6: tonefood = "Sml French Fries";
    break;
case 7: tonefood = "Bottled Water";
    break;
case 8: tonefood = "Lrg Soda";
    break;
case 9: tonefood = "Sml Soda";
    break;
}while (userInput.hasNextInt());

如果您想将所有选定的选项存储在变量'tonefood'中，您还需要将tonefood = /*item*/更改为tonefood += /*item*/ + " ";。

另外，不要提示用户用逗号分隔输入。将它们用空格分隔以自动获取下一个数字，因为逗号不能存储在int变量中。所以说你要输入数字1,2和3.输入应该是1 2 3而不是1, 2, 3或1,2,3。

用户需要在输入后输入非整数值才能终止输入。如果您想要提示用户，可以使用1 2 3 buy或checkout之类的内容。

希望这有帮助！

可以从switch语句输入多个数字吗？

1 个答案: