Explanation and its kinda cool

Ok I was reading that Sams book about C and whatever, they were talking about the != so I used it in an 'if else' statement, then I decided to try a 'do while' statement and when I compile it it looks weird, I can't explain it, can you guys tell me why it is doing this(code wise)and also why when you execute the program why it looks like it is over lapping.

Code:

---

#include <stdio.h>

int userNum;
int x=1;

int main(void)
{
        printf("Please enter the number 1: ");
        scanf("%d", &userNum);

        {
        if(userNum != x)
       
                printf("Hey! I told you to type the number 1 not %d\n\n", userNum);

                else
                        printf("Thank you for followind my instructions\n\n");
        }

        do
        {
                printf("This is the do part");
        }
       
        while(userNum == x);
       
       

        return 0;
}

---

Thanks.

P.S. I know why it is repeating cause I don't have a 'variable--' thing in it but why does it look so odd when you execute it?

Also how do you make it stop by using the -- thing, I tried while(userNum ==x; x--); but it wouldn't work, can someone help, this is my first attempt at these statement things.

I'm not sure what your code is supposed to do, so here's a version of it that keeps looping all the time the user enters the desired number. Hope this helps you understand.

Code:

---

#include <stdio.h>

int userNum;
int x = 1;

int main(void)
{
    do
    {
        printf("Please enter the number 1: ");
        scanf("%d", &userNum);

        if (userNum != x)
            printf("Hey! I told you to type the number 1 not %d\n\n", userNum);
        else
            printf("Thank you for followind my instructions\n\n");

        printf("This is the do part\n");
    } while (userNum == x);

    return(0);
}

---

Personally, I try not to use do-while loops, especially if there's a lot of code in them. It makes things harder to read, imho.

Thats ok Hammer, I don't know if I will try and use do while a lot in any code that I write, like I said though the book was giving examples so I tried it out as a test, I don't design these programs to be all that interesting because I am the only one that sees them, it is just for me to learn by but thanks.

Do while loops and while loops serve a great purpose, especially when a routine must be called over and over again. I find them very useful.

Be carefull though, a do while loop will work the routine and test the condition after the first iteration, where a while loop will test the condition first, then go into the routine.

Fun stuff to get to know and use.

Ya, I actually knew about the do this and then check with while to see if you have to do it again thing but thanks anyways, I will try out more loops as I go along.