uppercase and lowercase in c - uppercase

Question

I have tried to figure out why the program doesn't work. It turns lowercase to uppercase, let's say I type "k", it returns K. Then I continue typint "A", it doesn't return "a", but exits. But why? Here's the code:
#include <stdio.h>
#include <stdlib.h>
int main(){
char UPPER,LOWER;
printf("Enter UPPERCASE\n");
UPPER = getchar();
if (UPPER >= 65 && UPPER <= 90)
{
UPPER = UPPER + 32;
printf("The UPPERCASE now is %c\n", UPPER);
}
printf("Enter lowercase\n");
LOWER = getchar();
if (LOWER >= 97 && LOWER <= 122)
{
LOWER = LOWER - 32;
printf("The lowercase now is %c\n", LOWER);
}
getchar();
getchar();
}

Answer 1

If you compile and run this code:
void main(void)
{
char c = getchar();
printf("c = %d %c\n", c, c);
c = getchar();
printf("c = %d %c\n", c, c);
}
You will see this output:
user#host ~/work/tmp $ ./test
a
c = 97 a
c = 10
/* new line there*/
This code is not the same, but works:
#include <stdlib.h>
#include <stdio.h>
#define BUFSIZE 4
int main(void)
{
char UPPER[BUFSIZE] = {0}, LOWER[BUFSIZE] = {0};
int i;
printf("Enter UPPERCASE\n");
fgets(UPPER, BUFSIZE, stdin);
for(i = 0; i < BUFSIZE; i++)
{
if (UPPER[i] >= 65 && UPPER[i] <= 90)
{
UPPER[i] = UPPER[i] + 32;
}
}
printf("The UPPERCASE now is %s", UPPER);
printf("Enter LOWERCASE\n");
fgets(LOWER, BUFSIZE, stdin);
for(i = 0; i < BUFSIZE; i++)
{
if (LOWER[i] >= 97 && LOWER[i] <= 122)
{
LOWER[i] = LOWER[i] - 32;
}
}
printf("The LOWERCASE now is %s", LOWER);
return 0;
}

Answer 2

You should separately add getchar();, after printf("The UPPERCASE now is %c\n", UPPER);
and again after printf("The lowercase now is %c\n", LOWER);.
Most of the program is ending with getch(),and so we think that getch() is used to display the output...but it is wrong.It is used to get a single character from the console.
your correct code should be like this:
#include <stdio.h>
#include <stdlib.h>
int main()
{
char UPPER, LOWER;
printf("Enter UPPERCASE\n");
UPPER = getchar();
if (UPPER >= 65 && UPPER <= 90)
{
UPPER = UPPER + 32;
printf("The UPPERCASE now is %c\n", UPPER);
}
getchar();
printf("Enter lowercase\n");
LOWER = getchar();
if (LOWER >= 97 && LOWER <= 122)
{
LOWER = LOWER - 32;
printf("The lowercase now is %c\n", LOWER);
}
getchar();
}