Thread: Please help with last detail on this

Why does this code return all the grades as F, and not A B C or D

Code:

#include <stdio.h>

#define N 10

int main(void)

{

  double grade[N], highscore, average_score;
  int sum, numraise, studentname, i;
  char score;
  highscore=0.0;
  sum=0.0;

  printf("Enter %d grades: ", N);
  for ( i=0 ; i<N ;i++ )

  {
   scanf("%lf", &grade[i]);
   sum += grade[i];
   if (highscore < grade[i])
   highscore = grade[i];

 if (i >= 90.0)
 score='A';
 else if (i >= 80.0 && i< 90.0)
 score='B';
 else if (i >= 70.0 && i< 80.0)
 score='C';
 else if (i >= 60.0 && i< 70.0)
 score='D';
 else if (i < 60.0)
 score='F';
  }

 average_score= sum/10;

 for (studentname = 0; studentname < 10; studentname++)
 {


 printf("Student %d's grade is %.1lf, this is an %c\n", studentname+1, grade[stu
dentname], score);
 }
printf("The highest score is %.1lf\n", highscore);
printf("The average score is %.2lf\n", average_score);

return 0;
}

Thank you!

Why is every grade returned an A?

You're using i as your loop counter, and then comparing it to your grade constants.

There is no point within your current loop (when N is defined as 10) where i is anything greater than 60.

I think you want to compare the constants with grade[i] instead.

Oh, and in the interest of flexibility/ease-of-change, you might want to change average = sum / 10 to average = sum / N. Otherwise, if you change N you will get the wrong average.

Also, you will probably want to change N to a less common name. I think that the C preprocessor will still replace defined constants if they are in the middle of a word. For example, if you had a variable called Number, it would give you a compiler error because it would replace the N with 10. I don't think this is actually an issue in this particular piece of code, but it's good practice.

Agreed - Need guidance on project