Thread: Problem with functions

I'm going to be fairly active today in my questions as I am studying for a final. I wish I registered sooner; maybe I'd know a lot of this by now.

I guess I don't quite understand the mechanics of how the function works. I don't quite see how this points to that and that's probably why I'm making such kiddy errors.

This is the question I'm working on:

1. Write a function int isodd(int x) that returns 1 (i.e., true) if x is odd and returns 0 (i.e., false) if x is even. Put code to test the function in main().

Here is the code I wrote:

Code:

#include<stdio.h>
int isodd(int x);

main()
{
	int g, y;
	printf("Enter a number: ");
	scanf("%d", &g);
	y = isodd(g);
	printf("The number you have entered is %d\n", y);

}

int isodd(int x)
{

	int even, odd, h;

	if (x % 2 == 0)
		h == even;
	else
		h == odd;
	return h;
}

It compiles just fine, but anytime I input a number, the print function will say something along the lines of "The number you have entered is 734242342". Like I said, I'm guessing it's my misunderstanding of the way a function works.

For example, in my main function, I defined two variables: g and y. I set g equal to whatever the user inputs and I utilize y as a kind of pointer (probably misusing the word) to the isodd function. I don't really understand how the value entered, g, is relayed over to the function below, and that's my guess for why this is so hard for me.

I don't know if that complicated things, but yeah, I'm just basically asking for what's wrong with my function.

All help appreciated.

You want to use a single = to set a value. IE: h = even;. As currently you are not setting a value for h the function is returning whatever randoom junk was left in its register, which is why you get the weird output. Also, even and odd are undefined too. You will waant o set them to something, or just use a constant value.

1-even and odd are uninitialized junk integers when the function is called.
2- why are you using '==' here ?

This function is just

Code:

/*** Returns nonzero for odd values. ***/
int 
isodd (int value)
{
   return value % 2 != 0;
}

I don't think there is a reason to make it much more difficult than that, because your only goal is to return a distinct boolean result.