Making and Using STL Objects

Read Chapter 2 for an introduction to basic STL classes and their application.

Your first C++ program

Using the iostreams class

To declare the functions and external data in the iostrea,ms class, include the header file with the statement

#include <iostream>
The first program uses the concept of standard output, which means "a general-purpose place to send output". You will see other examples using standard output in different ways, but here it will just go to the console. The iostream package automatically defines a variable (an object) called cout that accepts all data bound for standard output.

To send data to standard output, you use the operator <<. C programmers know this operator as the "bitwise left shift," which will be described in the next chapter. Suffice it to say that a bitwise left shift has nothing to do with output. However, C++ allows operators to be overloaded. When you overload an operator, you give it a new meaning when that operator is used with an object of a particular type. With iostream objects, the operator << means "send to". For example:

cout << "howdy!";
sends the string "howdy!" to the object called cout (which is short for "console output").

That's enough operator overloading to get you started.