Even if you don't use pointers yourself, the code you'll learn from will have them. Suppose i is an integer. Setting a pointer to this value lets you refer indirectly to the variable i . This is useful if i is part of an array. In the following fragment, the pointer steps through an array.
Pointers are especially useful when functions operate on structures.
Using a pointer avoids copies of potentially big structures being made. To further illustrate the use of pointers let's suppose that in the first example on page we wanted to pass to the function mean the variable where we wanted the answer stored. Since we no longer need mean to return a value, we can make it return void . This won't work. The mean function doesn't know where answer is stored, so it can't change it.