A' ranks 97th, so you can write I =' a'+5; The value of the output I of the compilation run is 102.

A' ranks 65th in ASCII, which means that to convert lowercase letters into uppercase letters, you only need to subtract 32 yourself.

a b c d e f g h i j k l m n o p q r s t u v w x y z

A B C D E F G H I JK L M NO P Q RS T U V W XY Z

You can write programs like O 'Hea Maypie Jr.

# contains "stdio.h"

# contains "stdlib.h"

void main()

{

char a = ' A

for(int I = 0； I & lt26; i++)

printf("%c\n "，a+I)；

System ("suspended");

That's why you see the teacher can print letters without typing any letters.