Why is %c used in C?

Question

According to K&R C section 1.6, a char is a type of integer. So why do we need %c. And why can\'t we use %d for everything?

Answer 1

Because %d will print the numeric character code of the char:

printf("%d", 'a');

prints 97 (on an ASCII system), while

printf("%c", 'a');

prints a.