It is important to distinguish between a pointer, the address that the pointer holds, and the value at the address held by the pointer. This is the source of much of the confusion about pointers.

Consider the following code fragment:

theVariable is declared to be an integer variable initialized with the value 5. pPointer is declared to be a pointer to an integer; it is initialized with the address of theVariable. pPointer is the pointer. The address that pPointer holds is the address of theVariable. The value at the address that pPointer holds is 5. Figure 8.3 shows a schematic representation of theVariable and pPointer.

yourAge = *pAge;

The indirection operator (*) in front of the variable pAge means "the value stored at." This assignment says, "Take the value stored at the address in pAge and assign it to yourAge."

NOTE: The indirection operator (*) is used in two distinct ways with pointers: declaration and dereference. When a pointer is declared, the star indicates that it is a pointer, not a normal variable. For example,

unsigned short * pAge = 0; // make a pointer to an unsigned short

When the pointer is dereferenced, the indirection operator indicates that the value at the memory location stored in the pointer is to be accessed, rather than the address itself.

*pAge = 5; // assign 5 to the value at pAge

Also note that this same character (*) is used as the multiplication operator. The compiler knows which operator to call, based on context.

It is important to distinguish between a pointer, the address that the pointer holds, and the value at the address held by the pointer. This is the source of much of the confusion about pointers.

Consider the following code fragment:

int theVariable = 5;

int * pPointer = &theVariable ;