Fail to ask the user to repeat or exit the program using Do ... While loop in C

Question

I try to make a program that the output will be the classification based on the input grade (by character). Here is my code:

main ()
{
    char choice,grade;
    printf("Enter a grade: \n");
    scanf("%c",&grade);
    do
    {
        if (grade == 'a' or grade == 'A')
        {
            printf("Excellent!\nDo you want to continue?\n");
        }
        else if (grade == 'b' or grade == 'B')
        {
            printf("Good!\n Do you want to continue?\n");
        }
        else if (grade == 'c' or grade == 'C')
        {
            printf("Fair!\n Do you want to continue?\n");
        }
        else if (grade == 'd' or grade == 'D')
        {
            printf("Average!\n Do you want to continue?\n");
        }
        else if (grade == 'f' or grade == 'F')
        {
            printf("Weak!\n Do you want to continue?\n");
        }
        else
        {
            printf("Invalid!\n Do you want to continue?\n");
        }
        scanf("%c",&choice);
    } while (choice == 'y');
}

And this is the outcome of the code: enter image description here

It doesn't allow me to type yes or no. It just ends.

It would be very great if someone explain to me where I'm wrong since this is the first coding language that I learn and I am trying so hard to understand it by myself.

Answer 1

Your scanf() inside the do-while is getting skipped because when you press enter after inputting a grade, scanf() accepts it as a return character. So, do this instead: scanf(" %c", &grade).