Please help with basic recursive problem

[freshman]

Hi! I am very new to C programming. I have difficutly in understanding how the recursion work. One of my home work is to write a function using recursion to enter and display a string in reverse and state whether string contain any space - not to use array or string. I spent whole week but cannot list the space counted. Please help. Below is my code: (display string in reverse OK, but cannot count space:

#include <stdio.h>

void display(char);
int count(int);
int main(void)
{
char string;
printf("Enter a string:\n");
display(string) ;
printf("\n\n");
return 0;
}
void display(char ch)
{
int space;
ch = getchar();
putchar(ch);
if (ch != '\n')
display(ch);
putchar(ch);

[Banfa]

void display(char ch)
{
    int space;

    ch = getchar();
    putchar(ch);
    if (ch != '\n')
        display(ch);
    putchar(ch);
}

The is no need for ch to be a parameter of the function, you use it as a local variable only (i.e. the value passed in is not used)

Probably the easiest way to get the number of spaces would be to return it from display

unsigned display(void)
{
    char ch
    unsigned space;

    ch = getchar();
    putchar(ch);/* I think getchar echos the 
                  character anyway so this might be unrequired*/

    if (ch != '\n')
    {
        space = display(ch);
    }
    else
    {
        space = 0;
    }

    putchar(ch);

    if (ch == ' ')
    {
        space++;
    }

    return space;
}

[freshman]

Thank you very much for your solution, i appreciated.