reverse case
#include<stdio.h>
#include<ctype.h> // to use system defined function islower & toupper
int main()
{
printf("\n\n\t\tStudytonight - Best place to learn\n\n\n");
char alphabet;
printf("Enter an alphabet : ");
putchar('\n'); // to move to next Line
alphabet=getchar();
printf("\n\nReverse case of %c is : ",alphabet);
if(islower(alphabet))
putchar(toupper(alphabet));
else
// must be an uppercase character
printf("%c",tolower(alphabet)) ;
printf("\n\n\t\t\tCoding is Fun !\n\n\n");
return 0;
}