Question

如何让这个程序执行，我可以创建一个可以返回选择的循环吗？（你想再试一次吗？）

package javaapplication6;
import java.util.Scanner;

public class JavaApplication6 {  
  public static void main(String[] args) {
    Scanner a=new Scanner(System.in);
    int choose;
    System.out.println("MENU");
    System.out.println("1.Accounts");
    System.out.println("2.Age");
    System.out.println("3.Balance");
    System.out.println("4.Quit");
    System.out.println("Enter Selection:");
    choose=a.nextInt();

    switch(choose){
      case 1: 
        String name,password;
        System.out.println("Enter username:");
        name=a.nextLine();
        if("Nathalie".equals(name))
        {
          System.out.println("Enter password:");
          password=a.nextLine();
          if("Dandan".equals(password)){
            System.out.println("Welcome "+name+" "+password);
          }
          else
          {
            System.out.println("Invalid password");
          }
        }
        else
        {
          System.out.println("Incorrect Username!");
        }
        break;

      case 2:
        String na;
        int birthyear,age;
        System.out.println("Enter your name");
        na=a.nextLine();
        System.out.println("Enter your birthyear");
        birthyear=a.nextInt();
        age=2016-birthyear;
        System.out.println(""+na+" your age is "+age);
        break;
      case 3:
        int deposit,withdrawal,balance;
        System.out.println("Enter your deposit;");
        deposit=a.nextInt();
        System.out.println("Enter your withdrawal:");
        withdrawal=a.nextInt();
        balance=deposit-withdrawal;

        if(balance<0){
          System.out.println("Your account balance is not enough!");
        }
        else
        {
          System.out.println("Your balance is:"+balance);
        }
        break;
      case 4:
        System.out.println("Thank you for using this program");
        break;
      default:
        System.out.println("Invalid Selection");
        break;
    }
  }
}

Answer 1

您可以使用do-while循环。

boolean continue = true;

do {
   // your switch statement here:

   // Ask for termination: Do you want to contine? y/n
   // set continue accordingly
} while(continue );

您的程序将至少执行一次您的开关。询问用户是否要继续并在切换之前跳回。

Answer 2

虽然用户没有选择退出（在你的代码中，4）。打印选项，让用户再次选择。

do{
//your switch here
}while(choose!= EXIT_CODE);

如何让这个程序执行，我可以创建一个可以返回选择的循环吗？（你想再试一次吗？）

2 个答案: