java - 如何退出 switch 语句并返回到 While 循环？

Question

所以我正在尝试的是，在通过其中一项搜索获得足够的结果后，再转到另一项搜索。换句话说，我想退出 switch 语句并返回到 while 循环。我怎样才能做到这一点？

我有这个代码:

public static void main(String[] args) throws FileNotFoundException {


    String input = "";
    Scanner scan = new Scanner(System.in);
    System.out.println("Hello, input witch method you shall use(name, amount or date): ");
    input = scan.next();

    Warehouse storage = new Warehouse();
    //todo while loop kad amzinai veiktu. Ar to reikia ?
    while (!input.equals("quit")) {
        switch (input) {
            case "name":
                storage.searchByName();
                break;
            case "amount":
                storage.searchByAmount();
                break;
            default:
                System.out.println("Wrong input!");

        }

    }
}

Answer 1

一旦进入循环，您就永远不会更新input，因此您会返回到while循环(无限地)。有几种方法可以做到这一点，其中一种是 do while 循环。就像，

String helloMsg = "Hello, input which method you shall use(name, amount or date): ";
Scanner scan = new Scanner(System.in);
Warehouse storage = new Warehouse();
String input;
do {
    System.out.println(helloMsg);
    input = scan.next();
    switch (input) {
    case "name":
        storage.searchByName();
        break;
    case "amount":
        storage.searchByAmount();
        break;
    default:
        System.out.println("Wrong input!");
    }
} while (!input.equals("quit"));

另一种情况是无限循环，您可以使用quit来中断。就像，

String helloMsg = "Hello, input which method you shall use(name, amount or date): ";
Scanner scan = new Scanner(System.in);
Warehouse storage = new Warehouse();
loop: while (true) {
    System.out.println(helloMsg);
    String input = scan.next();
    switch (input) {
    case "name":
        storage.searchByName();
        break;
    case "amount":
        storage.searchByAmount();
        break;
    case "quit":
        break loop;
    default:
        System.out.println("Wrong input!");
    }
}

_{注意:它是 which不是witch .}