战舰游戏-例外

Question

我正在为赋值编写一个java程序，但有一个例外，用户不能为不存在的行或列输入值。i、 e如果电路板为5x7，且用户输入的列值为10，则屏幕将打印“错误：无效列”。然而，我不确定如何做这个最后的例外，我需要今天提交它。如果有人能帮忙，我会非常感激的！下面是我的makeGuess（）函数代码：

public void makeGuess(){
        //guesses is for keeping track of your guesses
        boolean cont=true;
        int rowGuess;
        int columnGuess;
        do{
        System.out.println("Enter a row to guess >");
        rowGuess = (input.nextInt()-1);
        if(rowGuess<=0){
            System.out.println("You did not enter a positive Integer.Please try again");
        cont=false;}
        else{
        cont=true;}
        }
        while (cont==false);


        do{
            System.out.println("Enter a column to guess >");
            columnGuess = (input.nextInt()-1);
            if(columnGuess <=0){
                System.out.println("You did not enter a positive integer.Please try again");
                cont=false;
            } else{
                cont=true;
            }
        }while(cont==false);

Answer 1

根据我的经验，更好的方法是创建自己的例外

public class BadMoveException extends Exception {
  BadMoveException(Exception ex) {
    super(ex);
  }

  BadMoveException(String ex) {
    super(ex);
  }
}

使makeGoogle抛出BadMoveException，然后对于用户可以进行的任何无效移动，您可以使用它创建一个BadMoveException，并将其打印在makeGoogle外部的catch{}块中

while (!gameOver) {
  try {
    makeGuess();
  }
  catch (BadMoveException ex) {
    System.out.println("You tried to make an invalid move:" + ex.getMessage());
  }
}

Answer 2

正如您有一个if语句来测试数字是否太小一样，您也需要测试数字是否太大

public void makeGuess(){
    //guesses is for keeping track of your guesses
    boolean cont=true;
    int rowGuess;
    int columnGuess;
    do{
        System.out.println("Enter a row to guess >");
        rowGuess = (input.nextInt()-1);
        if(rowGuess<=0){
            System.out.println("You did not enter a positive Integer.Please try again");
            cont=false;
        }else if(rowGuess>7){
            System.out.println("You did not enter a small enough Integer.Please try again");
            cont=false;
        }else{
            cont=true;
        }
    }while (cont==false);


    do{
        System.out.println("Enter a column to guess >");
        columnGuess = (input.nextInt()-1);
        if(columnGuess <=0){
            System.out.println("You did not enter a positive integer.Pleasetry again");
            cont=false;
        }else if(columnGuess>5){
            System.out.println("You did not enter a small enough Integer.Please try again");
            cont=false;
        } else{
            cont=true;
        }
    }while(cont==false);

Answer 3

假设您的其余代码有效，您可以简单地更改if语句以确保条目有效。

使用OR运算符||：

if (columnGuess <= 0 || columnGuess >= 10){
    System.out.println("Error: invalid Column");
}