Computer Programming and Database Handout

1. Computer Programming and Database Handout Computer Programming and Database Handout

2. Contents • Section A: Programming Basics • Section B: Procedural Programming • Section C: Object-Oriented Programming • Section D: Declarative Programming • Section E: Secure Programming • Section F: Database Programming Computer Programming and Database Handout

3. Section A: Programming Basics • Computer Programming and Software Engineering • Programming Languages and Paradigms • Program Planning • Program Coding • Programming Tools • Program Testing and Documentation Computer Programming and Database Handout

4. Computer Programming and Software Engineering • The instructions that make up a computer program are often referred to as code. • Programs can have millions of lines of code. • Developed by computer programmers • Computer programming Computer Programming and Database Handout

5. Computer Programming and Software Engineering Computer Programming and Database Handout

6. Programming Languages and Paradigms • Programming languages are made up of keywords and grammar rules designed for creating computer instructions. • Keywords can be combined with parameters. • Low-level languages typically include commands specific to a particular CPU or microprocessor family. • High-level languages use command words and grammar based on human languages. • The programming paradigm refers to a way of conceptualizing and structuring the tasks a computer performs. Computer Programming and Database Handout

7. Programming Languages • First generation language • The lowest level programming language; composed of binary digits; typically the only programming language understood by a CPU. • Machine language. • Second generation language • More user friendly than first generation language; uses mnemonics for people to use, such as ADD, SUB, MOV. • Assembly language. • Third generation language • Requires the programmer to specify, step-by-step, exactly how the computer must accomplish a task. Examples: C, Basic, FORTRAN. • Fourth generation language • allows the user to specify the desired result without having to specify step-by-step procedures. Examples: SAS, SPSS, APL. • Fifth-generation language • Based on a declarative programming paradigm. Lower Higher

8. Programming Paradigms • The programming paradigm refers to a way of conceptualizing and structuring the tasks a computer performs. Computer Programming and Database Handout

9. Hypertext Markup Language and Extensible Markup Language • Hypertext • An approach to data management in which data are stored in a network of nodes connected by links and are accessed through interactive browsing. • Hyperlinks • The links that connect data nodes in hypertext. • Hypertext document • The combination of nodes, links, and supporting indexes for any particular topic in hypertext. • Hypertext markup language (HTML) • The standard programming language used on the Web to create and recognize hypertext documents. • Extensible markup language (XML) • A programming language designed to improve the functionality of web documents by providing more flexible and adaptable data identification.

10. Comparison of HTML and XML

11. Program Planning • The problem statement defines certain elements that must be manipulated to achieve a result or goal. • You accept assumptions as true to proceed with program planning. • Known information helps the computer to solve a problem. • Variables vs. constants Computer Programming and Database Handout

12. Program Planning • Problem statement - Identify the pizza with the lowest price per square inch. • Assuming that there are two pizzas to compare, that both pizzas contain the same toppings, and that the pizzas could be round or square, and given the prices, shapes, and sizes of the two pizzas, the computer will print a message indicating which pizza has the lower price per square inch. Computer Programming and Database Handout

13. Program Coding A text editor such as Notepad allows programmers to enter lines of code using a familiar word processing interface. Computer Programming and Database Handout

14. Programming Tools • A Software Development Kit (SDK) is a collection of language-specific programming tools that enables a programmer to develop applications for a specific computer platform. • An Integrated Development Environment (IDE) is a type of SDK that packages a set of development tools into a sleek programming application. • A Component is a prewritten module, typically designed to accomplish a specific task. • An API is a set of application program or operating system functions that programmers can access from within the programs they create. Computer Programming and Database Handout

15. Program Testing and Documentation • A computer program must be tested to ensure that it works correctly. • Program errors include • Syntax errors • Runtime errors • Logic errors • A Debugger can help a programmer read through lines of code and solve problems. Computer Programming and Database Handout

16. Program Testing and Documentation • Remarks or “comments” are a form of documentation that programmers insert into the program code. Computer Programming and Database Handout

17. Section B: Procedural Programming • Algorithms • Expressing an Algorithm • Sequence, Selection, and Repetition Controls • Procedural Languages and Applications Computer Programming and Database Handout

18. Algorithms • Set of steps for carrying out a task that can be written down and implemented. • Start by recording the steps you take to solve the problem manually. • Specify how to manipulate information. • Specify what the algorithm should display as a solution. Computer Programming and Database Handout

19. Algorithms Computer Programming and Database Handout

20. Expressing an Algorithm • Structured English • Pseudocode Computer Programming and Database Handout

21. Expressing an Algorithm by a Flowchart • Flowchart • The pizza program flowchart illustrates how the computer should proceed through the instructions in the final program. Computer Programming and Database Handout

22. Expressing an Algorithm - Walkthrough • Perform a walkthrough to make sure thealgorithm works. Computer Programming and Database Handout

23. Sequence, Selection, and Repetition Controls • Subroutines, Procedures, and Functions • sections of code that are part of the program, but not included in the main sequential execution path. Computer Programming and Database Handout

24. Sequence, Selection, and Repetition Controls • Sequence Control structure Executing a GOTO command directs the computer to a different part of the program. Computer Programming and Database Handout

25. Sequence, Selection, and Repetition Controls The computer executes a decision indicated on the flowchart by the question in the diamond shape. • Selection Control structure Computer Programming and Database Handout

26. Sequence, Selection, and Repetition Controls • Repetition Control structure To execute a loop, the computer repeats one or more commands until some condition indicates that the looping should stop. Computer Programming and Database Handout

27. Procedural Languages and Applications • Popular procedural languages include FORTRAN, COBOL, FORTH, APL, ALGOL, PL/1, Pascal, C, Ada, and BASIC. • The procedural approach is best used for problems that can be solved by following a step-by-step algorithm. • Does not fit well with certain types of problems. • Produces programs that run quickly and efficiently. Computer Programming and Database Handout

28. Section C: Object-Oriented Programming • Programming language that encapsulates a small amount of data with instructions about what to do with data. • Methods: the instructions about what to do with encapsulated data objects. • Object: the combination of a small amount of data with the data. • Encapsulation: the process of creating an object. • Reusability feature: allows classes created for one purpose to be used in a different object-oriented program if desired. • Object-oriented Program Structure • Object-oriented Languages and Applications Computer Programming and Database Handout

29. Objects and Classes • An Object represents an abstract or real-world entity. • A Class is a template for a group of objects with similar characteristics. • A Class Attribute defines the characteristics of a set of objects. • Public vs. private attributes Computer Programming and Database Handout

30. Inheritance • Passing certain characteristics from one class to other classes. • Superclass • Subclass • Class hierarchy Computer Programming and Database Handout

31. Methods and Messages • A Method is a segment of code that defines an action. • Collect input, perform calculations, etc. • A method is activated by a message. • Can be defined along with the class they affect. • Polymorphism refers to the ability to redefine a Method in a subclass. • Helps simplify program code. Computer Programming and Database Handout

32. Object-Oriented Program Structure Computer Programming and Database Handout

33. Object-Oriented Program Structure Computer Programming and Database Handout

34. Object-Oriented Program Structure • When the pizza program runs, on-screen prompts ask for the shape, size, and price of each pizza; then the program displays a message that indicates which pizza is the best deal. Computer Programming and Database Handout

35. Object-Oriented Languages and Applications • SIMULA was believed to be the first object-oriented computer language. • The Dynabook project was the second major development in object-oriented languages. • Popular object-oriented languages today are Ada95, C++, (Visual Basic, and C#). • The OO paradigm results in decreased runtime efficiency, but allows encapsulation, which hides the internal details of objects and their methods. Computer Programming and Database Handout

36. Section D: Declarative Programming • The Declarative Paradigm • Prolog Facts • Prolog Rules • Input Capabilities • Declarative Languages and Applications Computer Programming and Database Handout

37. The Declarative Paradigm • Attempts to describe a problem without specifying exactly how to arrive at a solution. • A Fact is a statement for solving a problem. • Rules describe the relationship between Facts. • An approach to the programming process in which the programmer writes a program by specifying a set of statements and rules that define the conditions for solving the problem. Computer Programming and Database Handout

38. The Declarative Paradigm • A Decision Table is a tabular method for visualizing and specifying rules based on multiple factors. Computer Programming and Database Handout

39. Prolog Facts Computer Programming and Database Handout

40. Prolog Facts • You can query a program’s database by asking a question, called a Goal. The ?- prompt allows you to query a set of Prolog facts and rules. Computer Programming and Database Handout

41. Prolog Facts • Finding a value for a variable is referred to as Instantiation. Prolog uses a process called instantiation to satisfy goals. Computer Programming and Database Handout

42. Prolog Rules • The order of program instructions is critically important. Computer Programming and Database Handout

43. Input Capabilities When the pizza program runs, the pizzainfo rule collects input for the prices, the sizes, and the shapes of two pizzas. Computer Programming and Database Handout

44. Declarative Languages and Applications • Declarative programming languages are most suitable for problems that pertain to words and concepts rather than to numbers. • Highly effective programming environment. • Not commonly used for production applications. • Minimal input and output capabilities. • Poor performance on today’s personal computer architecture. Computer Programming and Database Handout

45. Section E: Event Driven Programming • A Visual Development Environment (VDE) provides programmers with tools to build substantial sections of a program. • Form design grid • Control • Properties • Event • Event-handling code Computer Programming and Database Handout

46. Program Coding (Event Driven) Controls, such as the Best Deal button, can be selected by a programmer from a properties list. Here a programmer is selecting the background color for the Best Deal button. Computer Programming and Database Handout

47. Program Coding (Event Driven) Computer Programming and Database Handout

48. Section F: Secure Programming • Black Hat Exploits • Secure Software Development • Mitigation Computer Programming and Database Handout

49. Black Hat Exploits • Today’s operating systems, utilities, and application software are full of defects that create security holes, which are exploited by black hats. • A buffer overflow (also called a buffer overrun) is a condition in which data in memory exceeds its expected boundaries and flows into memory areas intended for use by other data. Computer Programming and Database Handout

50. Black Hat Exploits Computer Programming and Database Handout