Why can the address of an array variable can not be assigned to a pointer? And what are 'Wfatal-errors'?

Question

I tried the below-pasted code and got an error:

cannot convert int (*)[6] to int* in assignment
compilation terminated due to -Wfatal-errors .

#include <stdio.h>

int my_array[] = {1,23,17,4,-5,100};
int *ptr;

int main(void)
{
    int i;
    ptr = &my_array;     /* point our pointer to the first
                                      element of the array */
    printf("\n");
    for (i = 0; i < 6; i++)
    {
      printf("my_array[%d] = %d   ",i,my_array[i]);   /*<-- A */
      printf("ptr + %d = %d\n",i, *(ptr + i));        /*<-- B */
    }
    return 0;
}

Answer 1

ptr = &my_array;

The type of &my_array is int (*)[6] while the type of ptr is int* . They're incompatible types.

What you should be doing is this:

ptr = my_array;

Now the type my_array is int[6] which decays into int* in the above context. So it works.

Answer 2

An array is convertible to a pointer. What you meant to do is:

ptr = my_array;

Answer 3

You have to use:

ptr = my_array;

Which is equivalent to:

ptr = &my_array[0];

Answer 4

All you need to do here is:

ptr = my_array;

There's no need to use the & operator.