1. Hello World 2
What does all that mean?

2. The Evolution of Programming Languages
Early computers programmed in machine language
To calculate wages = rate * hours in machine language:
//Load
//Multiply
//Store

3. The Evolution of Programming Languages (cont’d.)
Assembly language instructions are mnemonic
Assembler: translates a program written in assembly language into machine language

4. The Evolution of Programming Languages (cont’d.)
High-level languages
Express algorithms at a more abstract level: int wages = rate * hours;
Ex: Basic, FORTRAN, COBOL, Pascal, C, C++, C#, and Java
Current popularities

5. The Evolution of Programming Languages (cont’d.)
Compiler: translates a program written in a high-level language into machine language

6. Processing a C++ Program (cont’d.)
To execute a C++ program:
Create a text source program in C++
Preprocessor directives begin with # and are processed by the preprocessor
Compiler:
Checks that the program obeys the language rules
Translates into machine language (object program)

7. Processing a C++ Program (cont’d.)
To execute a C++ program (cont'd.):
Linker:
Combines object program with other programs provided by the SDK to create executable code
Library: contains prewritten code you can use

8. How the code works: # : preprocessor directive
Instructions to do before compiling
Bring the code from the library iostream into this file

9. How the code works:
Use all the names that are in the "standard" grouping in my program
Alternative:

10. How the code works:
; statement terminator
Ends a "sentence of code"

11. How the code works: int main() The starting point of our program
Program instructions go inside { }

12. How the code works: Comment : computer ignores
// : rest of line is comment
/* : everything is comment until */
/** : special comment – machine readable

13. Documentation
Every file should have comment like this at top:

14. How the code works:
cout : console output

15. How the code works:
cout : console output
<< "send to output"

16. How the code works: cout : console output << "send to output"
"Hello" : a string – piece of text

17. How the code works: cout : console output << "send to output"
"Hello" : a string – piece of text
endl : symbol representing "end of line"

18. How the code works: return 0 Program ran successfully
Anything BUT 0 indicates error

19. Working with numbers We can output numbers to console:
Can do math using + - / *
Division may give interesting results…

20. Everything Counts Indentation & Style matter (to humans)
Spelling & Capitalization matter (to humans & computers)

21. Exercises: Write a program that displays: Your Name Your Birthdate
Write a program that calculates and prints:
Hints: Have to write using / for division, * for multiplication, and ( ) for ordering
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