Using modulus operator on a char in C

Question

I am trying to mod a char in c by using the following:

int shift = 1;    
c = (c + shift ) % 26;
printf("c= %c \n",c);

The variable c is a lowercase english character between a-z. When I try to print out the char c using the above code, I get the following:

c=

Could someone please tell me what I am doing wrong?

The letter c doesn't have a value of less than 26. You might take a look at an ascii chart and see if that helps. — Retired Ninja, Aug 10 '16 at 23:37
You want `'a' + (c - 'a' + shift) % 26` if I understand correctly. — Alok--, Aug 10 '16 at 23:55

score 0 · Answer 1 · answered Aug 10 '16 at 23:44

0

Shift it by 'a' or 'A'. Then you'll always get a character that's part of the alphabet:

int main(){
    unsigned i;
    for(i=0;;i++)
        printf("i=%c\n", 'a'+i%26);

 }

prints:

i=a
i=b
i=c
i=d
i=e
i=f
i=g
i=h
i=i
i=j
...

answered Aug 10 '16 at 23:44

Petr Skocik

1 Answers1