1. What is Programming?
A program is a list of instructions that is executed by a computer to accomplish a particular task.
Creating those instructions is programming by a programmer

2. Programming language: Special language (like French or German)
Understood by the computer
Tells the computer what to do
Used by a programmer to write a program
Visual Basic, Java, C#, C++, COBOL
Machine language:
Language of the computer
Every “Programmer” language is converted to machine language
Consists of bits on or off only
Compiler or interpreter:
Software that translates programming languages to machine language

3. Using software to translate the program into machine language:
Coding the program:
Select the programming language
Write the instructions
Using software to translate the program into machine language:
Programmers write instructions in English-like high-level languages
Compilers or interpreters change the programs into low-level machine language that can be executed
Syntax errors are identified by the compiler or interpreter

4. Binary Machine Language – all data types consist of 1s and 0s
1 bit (0 or 1)
4 bits = nibble
1 byte = 8 bits = 2 nibbles
Is the storage for one character
1 word = 4 bytes
1 K = 1 KB = 1 kilobyte = 1,0240 bytes = 210 bytes
Kilo = 1,000 : 1 KB = 1,000 bytes
1 Meg = 1 megabyte (MB) = 1 million = 1024 KB
1 GB = 1 gigabyte (GB) = 1024 MB = 1,000,000,000
Many people approximate to steps of 1000, not 1024

5. Programming Languages
Machine Languages
Assembly Languages
One programmer instruction converted to 1 machine level instruction
ADD A,B
High-level Languages
Looks more like English words and algebraic expressions
Examples of high level languages
Programmer instruction converted to many machine level
ADA BASIC
C++ FORTRAN
COBOL Java
Pascal Visual Basic

6. Machine Language Generation
Programmer written computer code
Programmer written computer code
Translator (Interpreter) Program (browser)
Compiler
Assembler
One Machine Language Instruction
FUNCTION Browsers netscape MS Explorer Javascript PHP ASP
Many machine Language Instructions
.exe file
Execute
Execute
MS Word, Windows XP, MS Excel, Vista, MS Explorer

7. Writing Programs
To write a program in a high-level language, you need:
Appropriate software
A text editor to type and edit program statements
A debugger to help find errors in program code
A compiler or interpreter to translate the program into machine language

8. Error Types
Syntax: the rules governing word usage and punctuation in the language (format, recipe, formula)
Logic errors are more difficult to locate than syntax errors

9. Syntax Error Cycle

10. A program must be free of syntax errors to be run, or executed, on a computer
The program will not compile or be translated
A message will point out the offending instruction
To function properly, the logic must be correct
The program will still execute
The output may be incorrect
The program may exit prematurely
The program may ABEND (Abnormal Termination)
The program may execute with no errors/problems

11. Logic
A program must be free of syntax errors to be run, or executed, on a computer
To function properly, the logic must be correct
What’s wrong with this logic for making a cake?

12. Two major programming techniques:
Procedural programming
Object-oriented programming
Procedural programming: focuses on the procedures that programmers create
Object-oriented programming: focuses on objects that represent real-world things and their attributes and behaviors
Both techniques employ reusable program modules

13. Mainline Logical Flow Through a Program
Procedural program: one procedure follows another from beginning to end
Mainline logic has three distinct parts:
Housekeeping: steps to get ready
Main loop: instructions executed for every input record
End-of-job: steps taken at end of program
Break the logic down into at least three modules

14. Mainline Logical Flow Through a Program

15. Mainline Logical Flow Through a Program
Modularization of the program:
Keeps the job manageable
Allows multiple programmers to work simultaneously
Keeps the program structured

16. Housekeeping Tasks
Housekeeping tasks: include all steps that occur at the beginning of the program
Declare variables
Open files
Perform one-time-only tasks such as printing headings
Read the first input record

17. Annotate the Output
If the output consists of numbers or any data that has no explanatory text with it, you should annotate your output – this means to add some text so the user knows what the output means.