3.3
SCOPE RULES 117Local Variables 117Procedural Abstraction 120Global Constants and Global Variables 121Blocks 124Nested Scopes 124Tip: Use Function Calls in Branching and Loop Statements 125Variables Declared in a for Loop 125CHAPTER SUMMARY 126ANSWERS TO SELF-TEST EXERCISES 127PROGRAMMING PROJECTS 130this page intentionally blank)
3 Function Basics
Good things come in small packages.Common sayingI
NTRODUCTIONIf you have programmed in some other language, then the contents of this
chapter will be familiar to you. You should still scan this chapter to see the C++
syntax and terminology for the basics of functions. Chapter 4 contains the
material on functions that might be different in C++ than in other languages.
A program can be thought of as consisting of subparts such as obtaining
the input data, calculating the output data, and displaying the output data.
C++, like most programming languages, has facilities to name and code each
of these subparts separately. In C++ these subparts are called
functions. Most
programming languages have functions or something similar to functions,
although they are not always called by that name in other languages. The
terms
procedure,
subprogram, and
method, which you may have heard before,
mean essentially the same thing as
function. In C++ a function may return a
value (produce a value) or may perform some action without returning a
value, but whether the subpart returns a value or not, it is still called a func-
tion in C++. This chapter presents the basic details about C++ functions.
Before telling you how to write your own functions, we will first tell you how
to use some predefined C++ functions.
Predefined Functions
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