Question

When i try to compile the following code, i get the error

test.c: In function 'main':
test.c:16: error: incompatible types in assignment

and the code is..

#include <stdio.h>
#include <ctype.h>
#include <string.h>

typedef struct {
    char name[20];
    struct planet* next;
} planet;


int main(int argc, char *argv[])
{
    planet *p, *start, *first, *second, *third;

    strcpy(start->name, "Suthan");
    start->next = *first;

}

Answer 1

1) Allocate some memory to your pointers.

planet *start, *first; these are uninitialized pointers.

start->next // that's dereferencing an uninitialized pointer.

2) You’re setting start->next (a pointer to a planet) to a deferenced pointer first. That’s the root of your error.

start->next = *first;  // should be  = first;

3) Move the typedef name to get rid of the warning you were seeing.

typedef struct planet{
   char name[20];
   struct planet* next;
};