Write a program which has a function named upper which converts a lower case character value into its corresponding upper case character. The function does not return anything.
  #include <stdio.h>

void upper(char *);

int main(void)
{
char ch;

printf("\nEnter a character : ");
scanf("%c", &ch);

upper(&ch);

printf("\nConverted character = %c", ch);

return 0;
}

void upper(char *cp)
{
if(*cp >= 'a' && *cp <= 'z')
*cp = *cp - 32;
}