/* A concise comparison of * and & pointer operators
 * in C.
 * Matt Stephenson, November 2009
 * Build on command line with Visual C++ compiler:
 * >   cl /nologo /W4 pointers.c
 */
#include <stdio.h>

int main(void)
{
    int value;
    int *ptr;
    int **ptr2;

    printf("\nWe have:\n\nint value;\nint *ptr;\nint **ptr2;\n\n");
    printf("Let's assign our variables:\n\n");

    printf("value = 0xFF\nptr = &value;\n\n");
    value = 0xFF;
    ptr = &value;

    printf("Now let's observe * and & operators:\n\n");
    printf("value   is 0x%X\n", value);
    printf("*value  is illegal!!\n"); 
    printf("&value  is 0x%p\n\n", &value);

    printf("ptr     is 0x%p\n", ptr);
    printf("*ptr    is 0x%X\n",   *ptr);
    printf("&ptr    is 0x%p\n\n", &ptr);

    ptr2 = &ptr;

    printf("Now, go crazy:\n\n");
    printf("ptr2 = &ptr;\n\n");

    printf("ptr2    is 0x%p\n", ptr2);
    printf("*ptr2   is 0x%p\n", *ptr2);
    printf("**ptr2  is 0x%X\n", **ptr2);
    printf("&ptr2   is 0x%p\n", &ptr2);

    return 0;

}