如果用户输入特定数字，如何停止我的程序执行下一条语句？

Question

该程序提示用户输入一个奇数整数，该整数将决定特定菱形图案的高度。 即使用户输入列出的另一个数字之一，我的程序也会执行其他语句。

if ((number% 2 == 0)|| number <=0 )System.out.println("--- The number you entered is not odd positive!! Please try again!");

 else
    {if (number == 9)

        for (int row = 1 ; row < 10 ; row += 2) {
                    for (int col = 0 ; col < 10 - 1 - row / 2 ; col++)
                        System.out.print(" ");

                    for (int col = 0 ; col < row ; col++)
                        System.out.print("*");
                        System.out.println("");
                }

                for (int row = 7 ; row > 0 ; row -= 2) {
                    for (int col = 0 ; col < 9 - row / 2 ; col++)
                        System.out.print(" ");

                    for (int col = 0 ; col < row ; col++)
                        System.out.print("*");
                        System.out.println(""); }
                        System.out.println("Here is the diamond shape, whose height is " + number);

     //-----------------------------------------------------------------------

       if (number==7)

                for (int row = 1 ; row < 8 ; row += 2) {
                    for (int col = 0 ; col < 8 - 1 - row / 2 ; col++)
                        System.out.print(" ");

                    for (int col = 0 ; col < row ; col++)
                        System.out.print("*");
                        System.out.println("");
                }

                for (int row = 5 ; row > 0 ; row -= 2) {
                    for (int col = 0 ; col < 7 - row / 2 ; col++)
                        System.out.print(" ");

                    for (int col = 0 ; col < row ; col++)
                        System.out.print("*");
                        System.out.println("");}
                        System.out.println("Here is the diamond shape, whose height is " + number);
     //---------------------------------------------------------------------------

       if (number == 5)     

               for (int row = 1 ; row < 6 ; row += 2) {
                    for (int col = 0 ; col < 6 - 1 - row / 2 ; col++)
                        System.out.print(" ");

                    for (int col = 0 ; col < row ; col++)
                        System.out.print("*");
                        System.out.println("");
                }

                for (int row = 3 ; row > 0 ; row -= 2) {
                    for (int col = 0 ; col < 5 - row / 2 ; col++)
                        System.out.print(" ");

                    for (int col = 0 ; col < row ; col++)
                        System.out.print("*");
                        System.out.println("");}
                        System.out.println("Here is the diamond shape, whose height is " + number);
     //--------------------------------------------------------------------------

      if (number == 3)

               for (int row = 1 ; row < 4 ; row += 2) {
                    for (int col = 0 ; col < 4 - 1 - row / 2 ; col++)
                        System.out.print(" ");

                    for (int col = 0 ; col < row ; col++)
                        System.out.print("*");
                        System.out.println("");
                }

                for (int row = 1 ; row > 0 ; row -= 2) {
                    for (int col = 0 ; col < 3 - row / 2 ; col++)
                        System.out.print(" ");

                    for (int col = 0 ; col < row ; col++)
                        System.out.print("*");
                        System.out.println("");}
                        System.out.println("Here is the diamond shape, whose height is " + number);}

Answer 1

请注意您的编码风格。 您没有在if条件之后使用{ ，因此只有下一条语句与if条件有关。 我想用户只能输入一个数字，因此您应该使用else if条件，而只能使用other if 。

如果发布整个方法而不是其中的一部分，那会更好。

Answer 2

您可以添加“ break;” 或“继续；” 在每个选项的底部，具体取决于您是要突破还是继续执行这些选项。

还可以考虑使用Switch case语句（下面提供的代码未经测试，仅是示例）。

我不知道这是否适合您的需求，但似乎您有一个简单的数字列表可供选择-开关在这些情况下非常有用。 即：

pickANumber = sc.nextInt（）;

        switch (pickANumber) { 
           case 3: 
                for (int row = 1 ; row < 4 ; row += 2) {
                for (int col = 0 ; col < 4 - 1 - row / 2 ; col++)
                    System.out.print(" ");

                for (int col = 0 ; col < row ; col++)
                    System.out.print("*");
                    System.out.println("");
            }

                for (int row = 1 ; row > 0 ; row -= 2) {
                for (int col = 0 ; col < 3 - row / 2 ; col++)
                    System.out.print(" ");

                for (int col = 0 ; col < row ; col++)
                    System.out.print("*");
                    System.out.println("");}
                    System.out.println("Here is the diamond shape, whose height is " + number);}
              break;

           case 5: 
           for (int row = 1 ; row < 6 ; row += 2) {
                for (int col = 0 ; col < 6 - 1 - row / 2 ; col++)
                    System.out.print(" ");

                for (int col = 0 ; col < row ; col++)
                    System.out.print("*");
                    System.out.println("");
            }

            for (int row = 3 ; row > 0 ; row -= 2) {
                for (int col = 0 ; col < 5 - row / 2 ; col++)
                    System.out.print(" ");

                for (int col = 0 ; col < row ; col++)
                    System.out.print("*");
                    System.out.println("");}
                    System.out.println("Here is the diamond shape, whose height is " + number);
              break;

           case 7: 
           for (int row = 1 ; row < 8 ; row += 2) {
                for (int col = 0 ; col < 8 - 1 - row / 2 ; col++)
                    System.out.print(" ");

                for (int col = 0 ; col < row ; col++)
                    System.out.print("*");
                    System.out.println("");
            }

            for (int row = 5 ; row > 0 ; row -= 2) {
                for (int col = 0 ; col < 7 - row / 2 ; col++)
                    System.out.print(" ");

                for (int col = 0 ; col < row ; col++)
                    System.out.print("*");
                    System.out.println("");}
                    System.out.println("Here is the diamond shape, whose height is " + number);
              break;

           case 9:
           for (int row = 1 ; row < 10 ; row += 2) {
                for (int col = 0 ; col < 10 - 1 - row / 2 ; col++)
                    System.out.print(" ");

                for (int col = 0 ; col < row ; col++)
                    System.out.print("*");
                    System.out.println("");
            }

            for (int row = 7 ; row > 0 ; row -= 2) {
                for (int col = 0 ; col < 9 - row / 2 ; col++)
                    System.out.print(" ");

                for (int col = 0 ; col < row ; col++)
                    System.out.print("*");
                    System.out.println(""); }
                    System.out.println("Here is the diamond shape, whose height is " + number);
                break;

             default: System.out.println("Invalid option entered - please try again");