java - 输入错误后如何循环回到数组的开头

Question

第一篇文章在这里。我被指示更改我的代码以循环回数组的开头，并在用户输入无效内容(例如 0 或 5)后再次要求用户输入。如果有人能指出我正确的方向，我将不胜感激。

package lepackage;
import java.util.Scanner;
public class SwitchItUp {
    public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);
       System.out.println("Enter menu item:");
       int input = scanner.nextInt();
        String inputString;
        switch (input) {
            case 1:  inputString = "User want to Enter data";
                     break;
            case 2:  inputString = "User want to Display sata";
                     break;
            case 3:  inputString = "User want to Print data";
                     break;
            case 4:  inputString = "User want to Exit";
                     break;
            default: inputString = "Invalid Number";
                     break;
        }
        System.out.println(inputString);
    }
}

Answer 1

我会用一个 do...while 循环包围它

do {
//your code here
} while (!(input > 0 && input < 5));

See it online!