1. Spring 2013 CS 103 Computer Science – Business Problems Lecture 15: Intro to Programming
Instructor: Zhe He
Department of Computer Science
New Jersey Institute of Technology
12/8/2018

2. What Is a Computer Program?
Computer programs
Also called software
Are a list of instructions
Instructions are called code
CPU performs the instructions
Three types
Operating system
Utility
Application
Teaching tip
Chapters 7 and 8 cover software in great detail.

3. Software Is Stored In Many Files
Executable files
Contain the instructions for the CPU
Have extensions of .exe, or .com
Teaching tip
Open a folder and demonstrate each file. Show what happens when you open each file type.

4. Software Is Stored In Many Files
Dynamic link libraries
Partial executable file
Used to support executable files
Have .dll extensions

5. Software Is Stored In Many Files
Initialization files
Contain configuration settings for software
Have a .ini extension
Modern programs use the registry

6. Software Is Stored In Many Files
Help files
Contain information about the software
Information is indexed and searchable
Provides an online manual
Have a .chm or .hlp extension
Teaching tip
Most Windows programs provide help by hitting the Help menu or pressing F1. This will open the Windows Help program and display the help appropriate to the application that launched the help.

7. Software Is Stored In Many Files
Batch files
Used to automate tasks
Hold a series of OS commands
Have a .bat extension

8. Hardware/Software Interaction
Program execution
Software executes at the CPU level
Code to play a sound
Code generates an interrupt
CPU tells the sound card to play
Sound card plays the file
Programmer creates the code
Discussion point
Page 501 states “Computers are the reason people purchase computers”. This is an excellent quote. Have students list all the things that they do with computers. When done, point out that the majority of items are handled by a software application.

9. Hardware/Software Interaction
Code
Statements written in a programming language
Writing code can be tedious
Code must be perfect
Order of steps must be exact
Writing code is quite exciting
Problems are solved
New ideas are formed

10. Writing Code

11. Hardware/Software Interaction
Machine code
Recall that computers think in binary
Code is translated into machine code
CPU executes the machine code
CPUs have a unique machine code
Teaching tip
Figure 13A.4 on page 502 shows an example of binary code.

12. Hardware/Software Interaction
Programming languages
Simplifies the writing of code
English is used to describe the binary
Original code is called source code
Several hundred languages exist
Teaching tip
It is a good idea to show a few different programming environments. In particular, show the same program (Hello World works well) in several different languages. Point out that the result is the same, but the syntax is very different.

13. Hardware/Software Interaction
Compilers and interpreters
Converts source code into binary
Allows code to execute
Checks source code for correctness

14. Hardware/Software Interaction
Compiler
Creates an executable file
Contents are called object code
Executable can run on its own
Each language has its own compiler
C++ and Java are compiled languages

15. Hardware/Software Interaction
Interpreter
Runs program one line at a time
More flexible than compilers
Slower than compilers
Always needed to execute program
Visual Basic and Perl are interpreted

16. Planning a Computer Program
Plans
The steps to solve a problem
Describe the expected results
Programming without a plan is difficult
Teaching tip
Imagine driving from New York City to Los Angeles without a map, directions, cell phone or street signs. This is programming without a plan.

17. Planning Tools Pseudo code
Natural language statements that resemble code
Describes what must be done
Can be written by non programmers
Programmers develop unique versions

18. Compare two values and output the bigger one
12/8/2018

19. Order three number (increasing)
12/8/2018

20. Planning Tools Input-processing-output (IPO) charts
Determines what is needed
Input column
Data inputted by the user
Processing column
Pseudo code describing the problem solution
Output column
Desired output from the program

21. IPO Chart

22. How Programs Solve Problems
Program control flow
Order program statements are executed
Typically executed in order
Constructs can change the flow
Decision statements
Loops
Teaching tip
Briefly describe a loop and an if statement here.

23. How Programs Solve Problems
Algorithm
Set of steps
Always leads to a solution
Steps are always the same
Flowcharts can describe algorithms
Structured tool for drawing algorithms
Algorithms appear in all programs
Teaching tip
Figure 13A.8 on page 505 shows a flowchart.

24. Flowchart

25. How Programs Solve Problems
Heuristic
Set of steps
Solution is usually found
Solution may not be optimal
Used when algorithms fail
Algorithm is nonexistent or too complex
Appear in more complex applications
Data mining
Anti-virus software
Teaching tip
Data mining was introduced in chapter 11B.

26. Structured Programming
Programming using defined structures
Creates easy to read code
Programs are efficient and run fast
Several defined structures
Teaching tip
While lecturing, have a sample program open that incorporates all of the followings structures.

27. Structured Programming
Sequence structure
Describes the flow of the program
Typically executed in order
Branching statements allow multiple flows

28. Structured Programming
Selection statement
Also called conditional statement
Performs a true or false test
Determines which code to execute next
Teaching tip
Driving a car provides several examples of selection statements. The selection statements for an intersection with a traffic light provide three statements for discussion.

29. Structured Programming
Repetition statements
Also called looping structures
Repeats a section of code
Until an exit condition is reached
Teaching tip
Discuss the algorithm for walking up a flight of stairs. It becomes apparent that a loop is needed in the algorithm. The loop exits at the top of the stairs.

30. Object Oriented Programming
Also known as OOP
Enhances structured programming
Intuitive method of programming

31. Object Oriented Programming
Code reuse
Code used in many projects
Speeds up program development
Simplifies program development

32. Object Oriented Programming
Develops objects
All real world items are objects
OOP develops code versions
Contains data about the item
Contains functionality
Object encapsulates both into one package
Teaching tip
Provide an example of an object. I often use a lead pencil. Data includes the size and type of lead. Functionality includes write, erase, extendLead, extractLead and replenishLeadSupply.

33. Programming Languages
Used to generate source code
Avoids using machine code
Have strict rules of syntax
Symbols and punctuation have meaning
Spelling must be exact
Code is converted into machine language
Insider information
Older languages such as COBOL and Fortran actually required developers to place different coding statements in different columns on the screen.

34. Language Categories First generation language Machine languages
Written in binary
Different for every CPU

35. Language Categories Second generation languages Assembly languages
Statements that represent machine code
Code converted by an assembler
Still used to optimize video games

36. Language Categories Third generation languages (3GL)
First higher level language
Supports structured and OOP
Code is reusable
Code is portable
Typically written in an IDE
C/C++ creates games and applications
Java creates web applets
ActiveX creates Web and Windows applets

37. Language Categories Fourth generation languages (4GL)
Easier to use than 3GL
Coded in a visual IDE
Tools reduce the amount of code
Object oriented programming
Microsoft .Net is a language
Dream Weaver is an 4GL IDE

38. Microsoft.NET

39. Language Categories Fifth generation language (5GL) Mystery language
May not be created yet
Will create software automatically

40. WWW Development Languages
Markup languages
Describe how the text is formatted
Hyper Text Markup Language (HTML)
Basis of all web pages
Defines web structure using tags
Easy to learn and use
Created with a text editor

41. WWW Development Languages
Extensible Markup Language (XML)
Stores data in a readable format
Looks like HTML
Allows developers to create tags
Depends on HTML for formatting

42. XML

43. WWW Development Languages
Extensible HTML (XHTML)
Newer version of HTML
Stricter rules
Based on XML rules
Teaching tip
Be sure to emphasize that all web technologies at some point need HTML or XHTML to present data in a browser.

44. WWW Development Languages
Extensible Style Sheet Language (XSL)
Format and displays XML documents
Rules that dictate formatting
Create a standard web page

45. WWW Development Languages
Extensible HTML Mobile Profile
XHTML MP
Initially Wireless Markup Language (WML)
Creates pages viewable on a handheld

46. WWW Development Languages
Cascading Style Sheets (CSS)
Format HTML, XHTML and XSL
Applies consistent formatting to all pages
Teaching tip
Students wishing to learn about the web technologies should visit W3schools.com offers several free tutorials covering nearly every mainstream web technology.

47. WWW Development Languages
Web authoring environments
Reduces tedium for creating pages
Tools that simplify web site creation
Macromedia Dream weaver
Simplifies large sites
CSS support is exceptional
Microsoft FrontPage simplifies large sites
Macromedia Flash creates web animations
Teaching tip
For a fun example of what Flash can do, check out and watch the exploits of Strong Bad.

48. WWW Development Languages
Scripting languages
Create dynamic web pages
Change based on user input
HTML can create static pages
Page is generated as needed

49. WWW Development Languages
JavaScript
Developed by Netscape
Works inside of HTML
Page verification and simple animation
Based on Java

50. WWW Development Languages
Active Server Pages (ASP)
Developed by Microsoft
Based on Visual Basic
Good at connecting to Microsoft databases
Runs only on Microsoft servers

51. WWW Development Languages
Perl
Old UNIX language
Found on all Windows and Linux servers
Excellent web scripting language

52. WWW Development Languages
Hypertext Pre-Processor (PHP)
Especially good at connecting to MySQL
Very popular language
Runs on UNIX and Windows

53. Systems Development Life Cycle
SDLC
Organized way to build programs
Consists of five phases

54. Systems Development Life Cycle
Phase 1: Needs Analysis
Users identify a need
Need is clearly defined using tools

55. Systems Development Life Cycle
Phase 2: Systems design
Solution to the need is defined
Many tools are used
Prototypes of the solution are built

56. Systems Development Life Cycle
Phase 3: Development
Solution to the problem is built
Programmers write the solution
Technical writers document the process
Solution is continually tested

57. Systems Development Life Cycle
Phase 4: Implementation
The solution is installed
Users are converted to the new system
Trainers are important in this phase

58. Systems Development Life Cycle
Phase 5: Maintenance
IT professionals monitor the product
Bugs are found and fixed
New features are added