22.2 Pointer data type

Pointer data type in c++

A pointer variable is a variable that holds the address of a memory location. "Every variable is assigned a memory location whose address can be retrieved using the address operator&. The address of a memory location is called a pointer." Tony Gaddis, Judy Walters and Godfrey Muganda, Starting Out with C++ Early Objects Sixth Edition (United States of America: Pearson – Addison Wesley, 2008) 597. The pointer data type allows us to designate a variable to hold an address or a pointer. The concept of an address and a pointer are one in the same. A pointer points to the location in memory because the value of a pointer is the address were the data item resides in the memory. Given an integer variable named age:

int age = 47;

We can create a pointer variable and establish its value which would be the done using the address operator [which is the ampersand or&] by:

int * int_pointer =&age;

The asterisk is used to designate that the variable int_pointer is an integer pointer [int *]. This means that whenever we use the variable int_pointer that the compiler will know that it is a pointer that points to an integer.

In order to use pointers you will need to understand the indirection operator which is covered a supplemental link.

Definitions

pointer

A variable that holds an address as its value.