Thread: Passing structure to function

Originally Posted by Sereby

The following code fragment comes from Schildt's 4th Edition Complete C Reference:

Code:

/* Example of passing a structure pointer to a function */
/* Extraneous code deleted */

struct example {
    int member;
};

void function_example(struct example *ptr);

main (void)
{
    struct example passthis;

    function_example(&passthis);
}

void function_example(struct example *ptr)
{
    ptr -> member = 0;
}

Of course, it's Schildt's code, hence it's wrong, as usual..

Code:

int main (void)
{
    struct example passthis;

    function_example(&passthis);
   return 0;
}

My question is: Why is (&passthis) passed to the function instead of first initializing (ptr) to (&passthis) and then passing (ptr)?

It is exactly 'what function_example(&passthis)' does. There is no simpler or more straightforward way to do it.

If that were done, couldn't the function header be

Code:

function_example(*ptr)

Certainely not. Are you trying to rewrite the specifications of the language or what ?

Originally Posted by Sereby

The following code fragment comes from Schildt's 4th Edition Complete C Reference:

Code:

/* Example of passing a structure pointer to a function */
/* Extraneous code deleted */

struct example {
    int member;
};

void function_example(struct example *ptr);

main (void)
{
    struct example passthis;

    function_example(&passthis);
}

void function_example(struct example *ptr)
{
    ptr -> member = 0;
}

My question is: Why is (&passthis) passed to the function instead of first initializing (ptr) to (&passthis) and then passing (ptr)? If that were done, couldn't the function header be

Code:

function_example(*ptr)

?

You should do a seach for schildt on the board.