Functions Using Array Ranges

C++ functions that process arrays need to be informed about

The kind of data in the array
The location of the beginning of the array
And the number of elements in the array

The traditional C/C++ approach to functions that process arrays

Is to pass a pointer to the start of the array as one argument

And to pass the size [...]

More Array Function Examples

When you choose to use an array to represent data, you are making a design decision

But design decisions should go beyond how data is stored; they should also involve how the data is used

Often, you’ll find it profitable to write specific functions to handle specific data operations

(The profits here include increased program reliability, ease of [...]

The Implications of Using Arrays as Arguments

Let’s look at the implications of (A-1)

The function call sum_arr(cookies, ArSize)

Passes the address of the first element of the cookies array and the number of elements of the array to the sum_arr() function

The sum_arr() function

Assigns the cookies address to the pointer variable arr and assigns ArSize to the int variable n

This means (A-1) doesn’t really [...]

Creating a Reference Variable

C and C++ use the & symbol to indicate the address of a variable

C++ assigns an additional meaning to the & symbol

Presses it into service for declaring references

For example, to make rodents an alternative name for the variable rats, you could do the following (A-1):

Example of (A-1)

int rats;
int & rodents = rats; // makes rodents [...]

Structures

Sometimes it is useful to have a collection of values of different types and to treat the collection as a single item

For example, consider a bank certificate of deposit, which is often called a CD

A CD is a bank account that does not allow withdrawals for a specified number of months
A CD naturally has three [...]

Member Access Control: Public or Private?

You can declare class members

Whether they are data items or member functions

Either in the public or the private section of a class

But because one of the main precepts of OOP is to hide the data

Data items normally go into the private section

The member functions that constitute the class interface

Go into the public section

Otherwise, you can’t [...]

C++ Inline Functions

Inline functions

Are a C++ enhancement designed to speed up programs

The primary distinction between normal functions and inline functions

Is not in how you code them

But in how the C++ compiler incorporates them into a program

To understand the distinction between inline functions and normal functions

You need to peer more deeply into a program’s innards than we have [...]

The switch Statement

Suppose you create a screen menu that asks the user to select one of five choices—for example

Cheap
Moderate
Expensive
Extravagant
Excessive

You can extend an if else if else sequence to handle five alternatives

But the C++ switch statement more easily handles selecting a choice from an extended list

Here’s the general form for a switch statement (A-1):

Example of (A-1)

switch (integer-expression)
{
      case [...]

Strings

A string

Is a series of characters stored in consecutive bytes of memory

C++ has two ways of dealing with strings

The first, taken from C and often called a C-style string, is the first one this page examines
Later, we will discuss an alternative method based on a string class library

The idea of a series of characters stored [...]

for Loop Parts

A for loop provides

A step-by-step recipe for performing repeated actions

Let’s take a detailed look at how it’s set up

The usual parts of a for loop handle these steps:

Setting a value initially
Performing a test to see whether the loop should continue
Executing the loop actions
Updating value(s) used for the test

The C++ loop design positions these elements

So that [...]