1. Topic
Pre-processor
cout
To output a message

2. A sample C++ Program // sample C++ program #include <iostream>
comment
// sample C++ program
#include <iostream>
using namespace std;
int main() {
cout << "Hello World!";
return 0; }
compiler directive
use standard namespace
beginning of
function named main
beginning of
block for main
output statement
Pp55-58
string literal
send 0 to operating system;
exit main function
end of block
for main

3. cout Used to print out a message on the screen Not a keyword in C++
In order to use it, you have to include the file that defines cout --- “iostream.h”
Use “#include <iostream>” to do it
DEFINE BEFORE USE.
pp55 – header file
pp58, cout

4. The #include Directive
Inserts the contents of another file into the program
Do not place a semicolon at end of #include line
pp55

5. g++ g++ is a 3-in-1 command A preprocessor will A preprocessor
A compiler
A linker
A preprocessor will
Remove #include directives
Replace with copies of header files

6. using namespace std; A namespace is a collection of names.
Every name has to be unique
Uses standard namespace called std.
Ends with a semicolon
Follows #include directives in the code
Must appear in all programs
pp56

7. Function main int main ( ) { // function body return 0; }
Starting point of the program
Exactly one main function per program
pp56-57

8. Function A collection of related statements
Performs a specific operation
int
Specify return type of the function
Returns an integer when function finishes
( )
Parameters of the function
Empty ( ) means “no parameter needed”
pp57

9. cout Displays output on computer screen
Used together with the stream insertion operator << to send output to screen:
cout << "Programming is fun!";
<< can be used multiple times in an instruction
cout << “Programming " << “is fun!";
Or:
cout << “Programming ";
cout << “is fun!";
pp58

10. Two ways to start a new line
use the \n escape sequence (inside quotation marks)
cout << "Programming is\nfun!";
Or use the endl manipulator (outside quotations marks)
cout << "Programming is" << endl; cout << "fun!";
pp66

11. The endl Manipulator Do NOT put quotation marks around endl
The last character in endl is a lowercase L, not the number 1.
endl
This is a lowercase L

12. They will produce
Programming is
fun!

13. Escape characters Used within double quotes
Don’t get printed literally
\n starts a new line
\t inserts a tab
\\ prints a backslash \
\” prints a double quote
\’ prints a single quote
pp66

14. What does this program output?
// This program outputs a few sentences. #include <iostream> using namespace std; int main() { cout << “The works of Wolfgang\ninclude the following"; cout << “\nThe Turkish March” << endl;
cout << “and Symphony No. 40 “;
cout << “in G minor.” <<endl; return 0; }
=> This code will generate 5 lines of output

15. Structure of your program
Include directives
Using namespace
Write all instructions inside main( ) function
Compiler ignores all blank spaces except those inside quotation marks

16. Review C++ language elements How to use cout
Section 2.1 pages 54-59, 66
How to use cout