1. Chapter 3 Getting Started with C++
C++: An Active Learning Approach Todd Breedlove & Randal Albert Copyright © Jones and Bartlett Publishers All rights reserved.

2. 3.1 C++ Basics C++ is case sensitive
Average is different than average and AVERAGE
All C++ reserved words are in lowercase
Reserved words - identifiers that have special meaning and are a part of the language

3. 3.1 C++ Basics Most statements terminated by a semicolon except:
Function headers
Preprocessor directives
Control statements
Preprocessor directives - commands executed by the preprocessor
Preprocessor directives require the first character on the line to be a number sign (#)

4. 3.2 Whitespace
Whitespace - empty or non-visible character (i.e., space or tab), including blank lines
Aids readability
Readability allows a program to be more easily modified and maintained
Most whitespace is ignored by the compiler

5. 3.3 Comments
Comments - lines of C++ code that are ignored by the compiler
Used to document the source code for you or for other programmers
Aid in the readability and maintainability of source code

6. 3.3 Comments Two forms A block comment can span multiple lines
// inline comment
/* block comment */
A block comment can span multiple lines

7. 3.4 The main Function
Function - a group of related statements that perform a specific task or job
The main function (commonly referred to as “main”) is the starting point of a C/C++ program
Every C/C++ program will have exactly one main

8. 3.4 The main Function
Function header - first line in a function definition
Function definition - combination of the function header and a function body - the statements enclosed in curly braces
int main() // Function header, no semicolon
{// Start of function body
return 0; // C++ statement, requires semicolon
}// End of function body

9. 3.4 The main Function
Curly braces and parentheses always come in pairs
Curly braces:
Group statements together
Define the beginning and ending of the function body

10. 3.5 The #include Preprocessor Directive
Predefined routine - not part of the core language but an extension to the language
Part of the C++ standard
Accessed through header files
Preprocessor directive #include allows access to predefined routines in external or separate files - called header files

11. 3.5 The #include Preprocessor Directive
Two forms of the #include:
#include <header_file>
#include “header_file”
First example - looks in the “include” directory specified by the compiler
Used with predefined header files

12. 3.5 The #include Preprocessor Directive
Two forms of the #include:
#include <header_file>
#include “header_file”
Example 2 - looks for the header file in a user specified location
Used with user defined header files

13. 3.5 The #include Preprocessor Directive
The <iostream> header file contains predefined input and output routines
#include <iostream> // Allows access to I/O routines
int main() {
// Outputs "Hello World!" to the screen
std::cout << "Hello World!";
return 0; }

14. 3.5.1 Namespaces
namespace - allows grouping or structuring related entities inside one category
cout is located in “std” namespace

15. 3.5.1 Namespaces Ways to access routines in namespaces:
Explicitly std::cout << “Hello World”;
Using directive using namespace std;
Using declaration using std::cout;

16. 3.5.1 Namespaces
Explicit requires use of the namespace prefix every time a routine is used
Using directive allows access to all routines within a namespace
Using declaration allows access to only those routines specified

17. 3.7 C – The Differences
C programmers are limited to the block style comment (/* */) with older compilers
Many new C compilers allow the use of the inline comment (//) which has become part of the latest C standard

18. 3.7 C – The Differences
C uses different header files and routines for I/O
Namespaces are not required to access predefined functions
#include <stdio.h> // Allows access to I/O routines
int main( void ) {
// Outputs "Hello World!" to the screen
printf( "Hello World!" );
return 0; }