using pointer this way

Code:

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#include <stdio.h>
void test(int * total);

int main(void)
{
int total = 0;
void test(&total);
printf("The total is : %d", total);
return 0;
}

void test(int * total)
{
int number;
printf("Enter a number : ");
scanf("%d", &number);
*total = *total + number;
}

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Is it okay if I use it like this? Will there be any other issues that I will need to be worried about?

Quote:

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Is it okay if I use it like this?

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Yes - but for one detail...

Code:

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int main(void)
{
int total = 0;
void test(&total);
printf("The total is : %d", total);
return 0;
}

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Only specify the return type ("void" in this case) in the function declaration and the function definition, *not* when actually calling the function.

Quote:

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Will there be any other issues that I will need to be worried about?

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When you get deeper into learning about pointers? Yes. But with this batch of code - no.

Oops! What a silly mistake there for specifying void return type while calling the function. Thanks for the correction!
Hmm, I was worrying about not declaring the pointer and use it just like that.
And, the 'other issues' when I get deeper into learning about pointers have anything to do with the concept I used in the code?
*Not just the code, but the (int * total), without typing int *total in main/anywhere*

One question, when I type (int * total) , does that means that I declared total as the pointer at the same time?

Quote:

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I was worrying about not declaring the pointer and use it just like that.

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You declared the pointer in "test()" in the function definition.

You didn't declare a pointer to 'total' in main, but that's okay, because you passed the (&) address of 'total' to the function (which is equally valid - after all, a pointer holds the "address of" a variable).

This is very common - you should recognize this frequent use of code:

Code:

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int main(void)
{
    int x;

    printf("Enter an integer:  ");
    scanf("%d",&x);      // <--- right there!
    printf("You entered %d\n",x);

    return 0;
}

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Quote:

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And, the 'other issues' when I get deeper into learning about pointers have anything to do with the concept I used in the code?

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No, that was just my cute and ominous way of saying that the concept of pointers, and their applications, takes a while to fully grasp with full appreciation. But you're showing a great understanding so far, so keep going with it!

Quote:

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One question, when I type (int * total) , does that means that I declared total as the pointer at the same time?

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No "same time." You only declared a pointer to an integer (not an integer).

The variable "total" in "main()" (for which you pass the address) and the variable "total" in the "test()" function are different variables - it's a matter of scope.

Thanks! But still not 'great' enough. Still have to go through more basic concepts for pointer.

Quote:

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The variable "total" in "main()" (for which you pass the address) and the variable "total" in the "test()" function are different variables

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Mm, I think I got what you're trying to say there..

Quote:

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But still not 'great' enough

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I said, "so far" =)
But you're doing fine!

Code:

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void function1(int x);  // <--- this 'x'...

int main(void)
{
    int x = 0;  // <--- ...is not the same as this one
    int carrot = 1;
    function1(carrot);
    return 0;
}

void function1(int x)
{
    printf("X in function1 = carrot in main = %d\n",x);
}

// Output:  X in function1 = carrot in main = 1

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Quote:

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Originally Posted by Matticus

I said, "so far" =)
But you're doing fine!

Code:

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void function1(int x);  // <--- this 'x'...

int main(void)
{
    int x = 0;  // <--- ...is not the same as this one
    int carrot = 1;
    function1(carrot);
    return 0;
}

void function1(int x)
{
    printf("X in function1 = carrot in main = %d\n",x);
}

// Output:  X in function1 = carrot in main = 1

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Haha, thanks!

Ahh I see now! So I can just replace void function(int *x); with any other variables I see. Thanks man!