java - 当用户输入错误的输入时，我不知道如何重新启动循环

Question

好吧，对于一项作业，我需要创建一个循环，让用户输入数字 1-4 来表示剪刀石头布或结束游戏，但是如果他们输入了除这些以外的任何内容，我需要他们能够重新输入数字，但我似乎无法让我的循环重新启动或类似的事情......

代码(这只是我的 while 循环

while(user < 5)
          {
              System.out.println("Please enter in a number");
              computer = generator.nextInt(3) + 1;            
              user = keyboardIn.nextInt();

              //tell the player what was chosen
              if(user == 1)//player is rock
              {
                 System.out.println ("Player is rock");  
              }
              else if (user == 2)//player is paper
              {
                 System.out.println ("Player is paper");
              }
              else if (user == 3) //player is scissors
              {
                System.out.println ("Player is scissors");

              }
              else if (user == 4)
              {
                  System.out.println("Thank you for playing!");
                  break;
              }
              else if (user >= 5)
              {
                  System.out.println(user + " was never an option. \nTry again.");
                  user = keyboardIn.nextInt();
              }

              //tell the player what the computer has chosen
              if(computer == 1)//computer is rock
              {
                 System.out.println ("Computer is rock");
              }
              else if (computer == 2)//computer is paper
              {
                 System.out.println ("Computer is paper");
              }
              else if (computer == 3)//computer is scissors
              {
                 System.out.println ("Computer is scissors");
              }


              //determine winner
              if (user == computer) //tie
              {
                 System.out.println("It is a tie");
              }
              else if (user < computer) //player is rock
              {
                 System.out.println("Computer wins");
              }
              else //computer is scissors
              {
                 System.out.println("Player wins");
              }
              System.out.println();
          }

Answer 1

您可以使用继续跳回循环顶部。但请注意，在顶部您会要求用户输入，并且在出错时您也会这样做；这一次太多了。