1. Programming & S/W Development
Hun Myoung Park, Ph.D.,
Public Management and Policy Analysis Program
Graduate School of International Relations
International University of Japan

2. Outline Programming Languages Language Translators
Software Development
Software Analysis and Design
Programming
Implementation & Maintenance
Documentation

3. Programming Languages3
Programming Languages
To communicate between human beings and computers
Instruct a computer (H/W) to do what you want to do
Each computer can understand its own machine language only
Instructions are written in programming languages and then translated into the corresponding machine language.

4. Machine Language First generation language Consists of 1 and 04
Machine Language
First generation language
Consists of 1 and 0
Only language that computers can understand
Each computer has its own machine langue (machine dependent)
No translation
Difficult to write and read programs

5. Assembly Language Second generation language5
Assembly Language
Second generation language
Replace machine language’s binary codes for instructions and addresses with corresponding symbols and mnemonics
1:1 match
Translated by the assembler
More technical and faster
But less flexible and user friendly

6. High Level Languages 1 Less machine dependent6
High Level Languages 1
Less machine dependent
More readable and flexible (closer to human languages and farther away from machine language)
But less efficient (bigger and slower)
Need to be translated into a machine language (interpretation or compilation)

7. 7
High Level Languages 2
BASIC (Beginner’s All-purpose Symbolic Instruction Code)
FORTRAN (FORmula TRANslator) by IBM
COBOL (Common Business Oriented Language) by ANSI.
PL/1
Pascal
ADA

8. High Level Languages 3 C by Bell Lab C++, and Visual C8
High Level Languages 3
C by Bell Lab
C++, and Visual C
JAVA by Sun Microsystems
Web programming (script) languages: Perl, PHP, Python, Ruby

9. Types of Languages 1 First generation (machine language)9
Types of Languages 1
First generation (machine language)
Second generation (assembly language)
Third generation (high level language)
Forth generation (query languages)
Fifth generation (natural & intelligent languages)

10. 10
Type of Languages 2
Low-level languages (i.e., machine & assembly language)
High-level languages (e.g., C and Java)
Script languages (e.g., Perl, PHP, Python)

11. 11

12. Programming Paradigms12
Programming Paradigms
Procedural programming
Object-oriented programming
Functional programming
Declarative programming

13. Procedural Programming 113
Procedural Programming 1
Imperative or structured languages
Tells the computer what you want it to do step by step
FORTRAN, COBOL, BASIC, C, Pascal, Ada

14. Procedural Programming 214
Procedural Programming 2
Procedures (actions) & objects (data) are independent
Passive objects that cannot initiate an action by itself
A subprogram (routine or module) is a section of the program that performs a particular task when it is called from the main program.

15. Object-oriented Programming 115
Object-oriented Programming 1
Active Objects have both data and methods (procedures or actions)
Methods are not independent of but belong to the active object.
Objects need stimulus to perform actions
Visual Basic, Visual C, C++, Java, Smalltalk
Even in script languages (PHP & Python)

16. Object-oriented Programming 216
Object-oriented Programming 2
A class is an abstract blueprint of objects that have data and methods
An object is an (actualized) instance of the class (variables + actions)
A class of human beings (name, gender, height… + eating, sleeping, speaking …)
An object of human beings (Seohyun, 170cm, 40Kg … + eating milk, … )

17. Object-oriented Programming 317
Object-oriented Programming 3
class human {
public name …
public height … …
function eating (…) { }
function studying (…) {
...
} // end of class

18. Object-oriented Programming 418
Object-oriented Programming 4
Inheritance: a class can inherit from other classes. A class student inherits data and methods from a class human being and additionally has its own data and methods
Student = human beings + student’s data and methods
Faculty = human beings + faculty’s data and methods
Codes are reusable (minimize redundancy)

19. Object-oriented Programming 519
Object-oriented Programming 5
Data abstraction and decoupling: separating objects from classes
Encapsulation and information hiding: Data are bound closely with their methods.
Polymorphism enables to define methods with the same name that do difference things depending on classes.
A work() may mean teaching in a class faculty but farming in a class farmer.

20. Functional Programming20
Functional Programming
Define primitive functions and combine them to keep creating new functions
LISP (LISt Programming) & Scheme

21. Declarative Programming21
Declarative Programming
Logical reasoning to answer queries
Use deductive logic
Prolog
Report generators: query languages
Query languages: SQL (structured query language)
Application generators: Visual Basic, FOCUS

22. 22
Language Translators

23. Language Translators 1 Computer can understand machine languages only23
Language Translators 1
Computer can understand machine languages only
Language translators translate source codes into the machine language.
A source code file needs to be compiled and linked to be an object file, executable file.

24. 24
Language Translators 2
Lexer reads a source code (program) character by character and assembles characters into reserved words (token)
Parser performs syntactic analysis and converts tokens to nodes on a syntax tree.
Code generator produces segments of machine code of each node.
Optimizer inspects machine codes and eliminates redundancies.

25. Language Translators 3 Assembler translates a assembly program25
Language Translators 3
Assembler translates a assembly program
Interpreter (interactive)
Compiler (non-interactive, batch)

26. 26
Interpreter
Interactive way of communicating between users and machines.
Translates each line of the source programs one by one, run it without making an object file, and then return the result promptly.
Java source Bytecode by Java compiler  interpreted by JVM emulator
BASIC, LISP (LISt Processor) by MIT for artificial intelligence

27. 27
Compiler
Compiler translates a whole source code into an object code before executing it.
Most high level languages (e.g., C and Java) are translated by their compilers.
Source code  Object file  Linking libraries  Executable file
A library is a collection of commonly used modules that are combined into the executable file.

28. 28
Computer Software
A collection of well organized instructions that a computer executes to achieve specific tasks.
Algorithm or logic is a set of ordered steps to solve a problem.
Programming and coding (writing statements) is only a part of system development

29. 29
Software Development

30. 30
Software Development
In the system development stage, when customized software is needed
Program development life cycle (PDLC)
Problem clarification
Program design
Program coding
Program testing
Program documentation and maintenance

32. Problem Clarification32
Problem Clarification
Objectives and users (programming needs)
Output to be produced by the systems
Input required to get the desired output
Processing to transform input to output
Feasibility (e.g., budget, man powers, modification of old program?)

33. 33
Design the Program
Program logic in structured programming; modularization (subprogram or subroutine)
Design details
Pseudo-code (narrative outline)
Flowcharts
Control structure (logic structure)
Structured work-through to review

34. 34
Flowchart

35. Components of a Program35
Components of a Program
Variables (data type, constant, variable declaration and initialization)
Input and output
Expression (operators)
Statements (assignment, compound statement, control statements)
Subprogram: variables, parameters, call by value, call by reference

36. Control Structure Sequence Selection Iteration or loop If (else)36
Control Structure
Sequence
Selection
If (else)
switch (case)
Iteration or loop DO
FOR
WHILE

37. Control Structures 37 Selection (condition) Repetition (Loop)
If (score > 90) {
grade = “A”;
} elseif (score > 80) {
grade = “B”;
} else {
grade = “C”; }
for (i=1; i<x; 1) {
sum = sum + i;
while (i<x) {
sum = sum +1;
i = i + 1;

38. 38
Coding
A process of writing a program using a proper programming language
The result is a source code (program file in the text format)
Follow coding standards
Documentation (comments or remarks) makes it easy to understand and check mistakes.

39. 39
Compiling
Interpret a source code (program file) and convert into an object file
Source code  Compiling  Object file (object module) Linking  Executable file (load module)
Linking combines object files and built-in libraries (commonly used modules)

40. 40
Debugging
A process of checking and correcting errors (bugs) in a program
Errors
Syntax error
Logic error in the logic of a program
Run-time error occurs while a program is running

41. 41
Software Testing
To check if the software meets the requirements and works as expected
Unit testing (component testing), integration testing, system testing, and acceptance testing
Running programs with test data
Alpha test at developers’ site
Beta test or pre-release test (outside test)

42. Implementation and Maintenance42
Implementation and Maintenance
Implementation to run the program on the information systems
Installation and compatibility tests
Maintenance (updating)

43. Documentation Description of the program development Data dictionary43
Documentation
Description of the program development
Data dictionary
Documentation for users
Documentation for operators
Documentation for programmers
Documentation in source programs

44. 44
Conclusion
Software development is not the same as coding (programming).
Importance of software test .
Documentation in all stages.

45. References
Stair and Reynolds Principles of information systems, 12th ed. Cengage Learning.
Stair and Reynolds Information systems, 10th ed. Cengage Learning.
Morley and Parker Understanding computers, 15th ed. Cengage Learning.
Hutchinson and Sawyer Computers, Communications, and Information, 7th ed. Irwin/McGraw-Hill