在尝试确定平均成绩时，我不断收到此错误，

Question

   double average = calcAverage(grade1, grade2, grade3, grade4, grade5);
   System.out.println("The average is: ");
   determineGrade(average);

   public static double calcAverage(int grade1, int grade2, int grade3, int grade4, int grade5) {
      double average = (grade1 + grade2 + grade3 + grade4 + grade5) / 5;
      return average;        
  }

我一直收到determineGrade(average)的错误，错误说明：

  

此方法必须返回double类型的结果

Answer 1

您的所有输入都是整数。所以你的结果将是一个int。您需要将至少一个int转换为double，然后您的结果也将是双倍。

双倍平均值=（双倍）（1级+ 2级+ 3级+ 4级+ 5级）/ 5

Answer 2

那是因为在determineGrade你没有回报任何东西。你只打印一些东西，但什么也不返回。因此，请将determineGrade的返回类型设为void，或者至少让它返回double中的某些内容。

Answer 3

Ok sorry, but the rest of the code comes as follows,


import java.util.*;

  public class Stock
{
  public static void main (String[] args)
  {
     int grade1=0;
     int grade2=0;
     int grade3=0;
     int grade4=0;
     int grade5=0;

  // All of the below are gathering input from user
  System.out.println("What is the first grade?");

   Scanner input = new Scanner(System.in);
   grade1=input.nextInt();

   System.out.println("What is the second grade?");
    Scanner input2 = new Scanner(System.in);
    grade2=input.nextInt();

    System.out.println("Whar is the third grade?");
    Scanner input3 = new Scanner(System.in);
    grade3=input.nextInt();

   System.out.println("What is the fourth grade?");
   Scanner input4 = new Scanner(System.in);
   grade4=input.nextInt();

   System.out.println("What is the fifth grade?");
   Scanner input5 = new Scanner(System.in);
   grade5=input.nextInt();


   double average = calcAverage(grade1, grade2, grade3, grade4, grade5);

   System.out.println("The average is: ");

     determineGrade(average);

  }
  public static double calcAverage(int grade1, int grade2, int grade3, int grade4, int grade5)
  {
    double average = (grade1 + grade2 + grade3 + grade4 + grade5) / 5;

        return average;

  }

  public static double determineGrade(double average)


    {

        if (average>90)

        {

            System.out.println("You got an A");

        }

        else if (average>=80)

        {

            System.out.println("You got a B");

        }

        else if (average>=70)

        {

            System.out.println("You got a C");

        }

        else if (average>=60)

        {

            System.out.println("You got a D");

        }
        else if (average<60)



        {

            System.out.println("You got an F");


        }
    }
  }