CODEWITHSUNDEEP
c
user14947646
user14947646

Reputation:

Not a number output in c while trying to count average

I'm trying to tell the user to insert numbers as many as they can, and insert -1 if they want to terminate. The program is working good, but I tried to enter -1 as a first number and I got this output : -nan

This is the code :

 main()
{
     int counter = 0;
     float grade;
     float total = 0;
     float average;
     printf("Compute the average grades.\n");
     printf("Grade = -1 will terminate the process\n");
     printf( "Enter grade (-1 to terminate): " );
     scanf("%f",&grade);
     while(grade != -1)
     {
         counter++;
         total+=grade;
         printf( "Enter grade (-1 to terminate): " );
         scanf("%f",&grade);
     }
     average = total / counter;
     printf("Class average is %.2f\n", average);

}

Upvotes: 0

Views: 76

Answers (1)

Yunnosch
Yunnosch

Reputation: 26703

The problem is

average = total / counter;

when counter is 0, which it is when you never iterate the loop body even once.

Wrap that line (and maybe the following output) into a

if(counter>0)
{
    //...
}

with a following

else
{
    //...
}

You can output something like
"No numbers, no average. ;-)".

Upvotes: 1

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