Pointers, Cont.

A pointer may also be defined as a variable. The "normal" value in the pointer is the location to which it points

       int i = 1;
       int *ptr;

       ptr = &i;

       printf ( "The value of i is %d and the address of i is 0x%x\n", i,
                (unsigned int) ptr );

Since ptr and i now reference the same value then ptr may be dereferenced to produce the value

       printf ( "The value of i is %d and the address of i is 0x%x\n", *ptr,
                (unsigned int) &i );

The variable type of the pointer defines how the data will be represented when the pointer is dereferenced. This type is also useful when moving the pointer through memory.

Pointers are not automatically defined to any particular address. It is common to assign pointers to NULL and many functions will do this as a return value.