In this chapter, you start to learn about pointers. Pointers are extremely important for several reasons. First, pointer parameters enable you to circumvent C's call-by-value convention by which parameters are copied into at call time and out of at return time. Second, pointers provide an alternate way to access array elements. Third, pointers make it possible for your programs to ask for more memory only when those programs need more memory, thus reducing your need to estimate how much memory is likely to be necessary.

In this chapter and in the hardcopy version of this book, you learn how to use pointers in the first way, to circumvent C's call-by-value convention.