pass structure to function

ok im messing around with structures again
and i cant seem to pass the structure to the function

Code:

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#include <stdio.h>
#include <stdlib.h>


struct record_format {
      char name[BUFSIZ];
      int age;
      };

void display(struct record_format);       



int main(int argc, char *argv[])
{
 

  struct record_format record[] = {
        { "john", 21 },
        { "larry", 22 }
          };

 
display (record);

                               
 
getchar();
}

/************************************************************************/

void display(struct record_format rec)
{
    int i;
    for(i=0;i<2;++i)
  printf("name is &#37;s \nage is %d \n", rec.name, rec.age);

}

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Quote:

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24 C:\Dev-Cpp\mainffff.c incompatible type for argument 1 of `display'

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when i add the name and age to the structure is when it wont pass anymore!

Code:

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display (record[0]);
display (record[1]);

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display() takes a record_format struct, but you are passing an array of record_format structs.

And why do you want to pass a struct instead of pointer? passing struct will copy the whole struct contents to the temp var...

Code:

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void display(struct record_format* pRec)

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To pass the array via a pointer. Works for both the entire array or just one element.

Quote:

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Originally Posted by Elysia

Code:

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void display(struct record_format* pRec)

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To pass the array via a pointer. Works for both the entire array or just one element.

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yes you can use this type of passing...

thank you everyone
that replied. i got it working with a pointer.

here is my function to take in the struct
and i want to check if there are any empty
seats not taken. DR Power seat 21

Code:

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struct fast_line {          // structure
      char pass_name[ 30 ];
      int seat_number;
      };

---

Code:

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struct fast_line record[] = {    /** fill seats wth passengers **/
        { "DR Power", 21 },
        { "Green Lantern", 2 },
        { "The Flash" , 30 },
        { "Super Girl" , 7 },
        { "Phoenix", 12 },
        { "Clark Kent", 17 },
        { "The Tick" ,4 },
        { "Swamp Thing" , 26 }
       
          };

---

Code:

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void show_seats_taken( struct fast_line *rec )
{
 int i, length;
 int temp;
 length = strlen(rec->pass_name);
    for( i = 0; i < length; i++ )
      printf( "Seat [&#37;i] is assigned to %s \n\n",  rec[ i ].seat_number , rec[ i ].pass_name );
        if( rec[i].seat_number ==' ' ) // this is not working
        {
      temp = rec[i].seat_number;
      printf("seat %i is available\n" , temp );
    }
    }

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so im trying to find the empty spaces in the array of structs. there are 30 available how many are not filled..

and why you suppose that the number of members in your array is equal to the length of the name of the first passanger? What is the mysterios connection between these two magic numbers?

Quote:

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Originally Posted by vart

and why you suppose that the number of members in your array is equal to the length of the name of the first passanger? What is the mysterios connection between these two magic numbers?

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I suppose your talking about this?

Code:

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length = strlen(rec->pass_name);

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vart is being sarcastic.
The length of the name of the first passenger is NOT the length of the array,
One possible way to do is to pass another argument that indicates length.
When passing the structure, do sizeof(rec) / sizeof(rec[0]).

Quote:

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sizeof(rec) / sizeof(rec[0])

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will not work inn this case. rec is a pointer, so its size is 4 bytes on 32-bit system

Yes, but I assume it's declared on the stack before being passed to the function, in case it will work.

Quote:

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Originally Posted by Elysia

Yes, but I assume it's declared on the stack before being passed to the function, in case it will work.

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Try it. It won't.

Quote:

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Originally Posted by MacGyver

Try it. It won't.

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Maybe its just bad wording.

It will work if we declare array of structs and then pass its size as shown.

It will not work if we try to determine the array size in the function called

Yes, I was referring to your post where you mentioned that sizeof on a function parameter that is a pointer won't work.

Yes, to avoid confusing, the sizeof should be applied BEFORE the function and the size (or elements) passed TO the function since it cannot determine the size.

if this is what your talking about, it did what i wanted it to do.. or so ithink it did

Code:

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length = strlen(rec->pass_name);
    for( i = 0; i < length; i++ )
      printf( "Seat [%i] is assigned to %s \n\n",  rec[ i ].seat_number , rec[ i ].pass_name );

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Code:

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Seat [21] is assigned to DR Power
Seat [2] is assigned to Green Lantern
Seat [30] is assigned to The Flash
Seat [7] is assigned to Super Girl
Seat [12] is assigned to Phoenix
Seat [17] is assigned to Clark Kent
Seat [4] is assigned to The Tick
Seat [26] is assigned to Swamp Thing

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i am aware that i went about this whole project if you will the wrong way.. i think i set up the struct wrong to begin with..
thx
everyone

is this what you wanted? is this better than
length = strlen(rec->pass_name);

Code:

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struct fast_line record[] = {    /** fill seats wth passengers **/
        { "DR Power", 21 },
        { "Green Lantern", 2 },
        { "The Flash" , 30 },
        { "Super Girl" , 7 },
        { "Phoenix", 12 },
        { "Clark Kent", 17 },
        { "The Tick" ,4 },
        { "Swamp Thing" , 26 }
       
          };

size_t count = (record, sizeof(record) / sizeof * record );
show_seats_taken (record, count );


void show_seats_taken( struct fast_line *rec,  size_t size )
{
 int i, length;
 //char temp[BUFSIZ];
 
// length = strlen(rec->pass_name);
    for( i = 0; i < size; i++ )
      printf( "Seat [%i] is assigned to %s \n\n",  rec[ i ].seat_number , rec[ i ].pass_name );
   
   
    }

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