1. Computers Are Your Future Twelfth Edition*
Computers Are Your Future Twelfth Edition
07/16/96
Chapter 11: Programming Languages and Program Development
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

2. Programming Languages and Program Development*
07/16/96
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

3. Objectives Explain what a programming language is and how it works.*
Objectives
07/16/96
Explain what a programming language is and how it works.
Explain the development of programming languages over the years and the benefits and drawbacks of high-level programming languages.
Explain how object-oriented languages attempt to remedy the shortcomings of earlier languages.
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

4. *
Objectives
07/16/96
List several popular object-oriented languages and explain their advantage over older languages.
List the six phases of the program development life cycle (PDLC) and explain why the PDLC is needed.
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

5. *
Objectives
07/16/96
Explain why defining the problem in a top-down design manner leads to programs that are easier to debug and maintain.
Differentiate between problems that can arise in the testing and debugging phase as syntax and logic errors.
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

6. Programming Languages and How They Work*
Programming Languages and How They Work
07/16/96
Programming
Process used to create software programs
Programmers
People who use programming languages to create software applications
Programming languages
Consist of a vocabulary and a set of rules called syntax
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

7. Programming Languages and How They Work*
Programming Languages and How They Work
07/16/96
Interface
Point of interaction between components, such as the interaction between a user’s screen and the computer code, which results when running a program
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

8. Development of Programming Languages*
07/16/96
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

9. Development of Programming Languages*
Development of Programming Languages
07/16/96
Compilers and interpreters
Source code—programming instructions in the original form needed to translate a form that the computer can understand
Code—programming instructions created by the programmers
High-level language—language that mimics English; does not require a programmer to understand the intimate details of how hardware, especially the processor, handles data
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

10. Development of Programming Languages*
07/16/96
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

11. Development of Programming Languages*
Development of Programming Languages
07/16/96
Compilers and interpreters
Compiler—utility program translates source code into object code
Executable program—code transformed from object code ready to run programs that do not need to be altered
Interpreter—translation program that does not produce object code—translates one line of source code at a time; executes the translated instruction
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

12. Development of Programming Languages*
Development of Programming Languages
07/16/96
Five generations of programming languages
Machine
Assembly
Procedural
Nonprocedural
Natural
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13. Development of Programming Languages*
Development of Programming Languages
07/16/96
First-generation languages
Machine language
Based on binary numbers
Only programming language that a computer understands directly
Machine dependent
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

14. Development of Programming Languages*
Development of Programming Languages
07/16/96
Second-generation language
Assembly language
Low-level language
Programs use:
Mnemonics—brief abbreviations for program instructions make assembly language easier to use
Base-10 (decimal) numbers
Must be translated into machine language by an assembler
Occasionally used to create device drivers
Programs to control devices attached to a computer and game console programs
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

15. Development of Programming Languages*
Development of Programming Languages
07/16/96
Third-generation languages
High-level languages—do not require programmers to know details relating to the processing of data
Easier to read, write, and maintain than assembly and machine languages
Source code must be translated by a language translator
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

16. Development of Programming Languages*
Development of Programming Languages
07/16/96
Third-generation languages (con’t.)
Spaghetti code—difficult to follow, messy in design, prone to errors due to numerous GOTO statements
Structured programming—set of quality standards; programs more verbose but more readable, reliable, and maintainable
GOTO statements forbidden
Examples:
Ada
Algol
Pascal
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

17. Development of Programming Languages*
Development of Programming Languages
07/16/96
Third-generation languages (con’t.)
Modular programming—dividing larger programs into separate modules, each takes care of a specific function
Information hiding—also known as encapsulation, modular programming makes it possible to hide details in sensitive applications
Programming languages include:
Fortran C
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

18. Development of Programming Languages*
Development of Programming Languages
07/16/96
Procedural languages
Provide detailed instructions that are designed to carry out a specific action such as printing a formatted report
Nonprocedural languages
Do not require programmers to use step-by-step instructions
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

19. Development of Programming Languages*
Development of Programming Languages
07/16/96
Fourth-generation languages
Nonprocedural languages
Do not require step-by-step procedures
Examples
Report generators (database reports)
Query languages
SQL (Structured query language)—enables users to phrase simple or complex requests for data
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

20. Development of Programming Languages*
Development of Programming Languages
07/16/96
Fifth-generation languages
Natural language
Still being perfected
Nonprocedural
Use everyday language to program
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

21. Development of Programming Languages*
Development of Programming Languages
07/16/96
Object-oriented programming (OOP)
Programming technique based on data being conceptualized as objects
Object—unit of computer information that defines a data element that is used to model real-world objects
Attributes define the data
Procedures or operations are called methods
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

22. Development of Programming Languages*
Development of Programming Languages
07/16/96
Object-oriented programming (OOP) (con’t.)
Class—blueprint or prototype from which objects are made
Inheritance—ability to pass on characteristics from a class to subclasses
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

23. Development of Programming Languages*
Development of Programming Languages
07/16/96
Program development methods
Rapid application development (RAD)
Reuses prebuilt objects
Possible because of OOP
Joint application development (JAD)
Uses a team approach
Involves end users throughout development
Agile software development techniques—use collaboration between teams to develop solutions to meet customer needs and company goals
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

24. Development of Programming Languages*
Development of Programming Languages
07/16/96
Middleware
Makes connections between applications on multiple networks
Integral to modern information technology based on XML, Web services, and service-oriented architecture
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

25. A Guide to Programming Languages: One Size Doesn’t Fit All*
A Guide to Programming Languages: One Size Doesn’t Fit All
07/16/96
Early high-level languages
COBOL (Common Business-Oriented Language)
Used for business applications
Current focus is on editing aged code on mainframe computers
Fortran (formula translator)
Used for scientific/math/engineering applications
Being replaced by object-oriented and formula-solving programs
Mathematica
Used to handle all aspects of technical computing in a coherent and unified way
Can manipulate a wide range of objects, using only a small number of basic elements
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

26. A Guide to Programming Languages: One Size Doesn’t Fit All*
A Guide to Programming Languages: One Size Doesn’t Fit All
07/16/96
Structured and modular languages
Required for large-scale program development
Languages in widespread use:
Ada
BASIC
Visual Basic
Event-driven programming language that executes only in response to user actions C
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

27. A Guide to Programming Languages: One Size Doesn’t Fit All*
A Guide to Programming Languages: One Size Doesn’t Fit All
07/16/96
Object-oriented languages
Visual Studio.NET—Microsoft’s answer to Java and JavaScript
Visual Basic.Net
Visual C++
Visual C#
F#—language that combines object-oriented features with the assets of a functional language
Functional language reflects the way people think mathematically—useful in programs that express findings in mathematical form
Integrated development environment (IDE)
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

28. A Guide to Programming Languages: One Size Doesn’t Fit All*
A Guide to Programming Languages: One Size Doesn’t Fit All
07/16/96
Web-based languages
Not considered programming languages
Tell the browser how to display text and objects
Language types
Markup
Scripting
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

29. A Guide to Programming Languages: One Size Doesn’t Fit All*
A Guide to Programming Languages: One Size Doesn’t Fit All
07/16/96
Markup languages
Composed of a set of codes, or elements, that uses tags to define how text and objects display
Tags—markers that usually come in pairs
Content—text that displays, lies between the opening and closing tags
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

30. A Guide to Programming Languages: One Size Doesn’t Fit All*
A Guide to Programming Languages: One Size Doesn’t Fit All
07/16/96
Markup languages
HTML (Hypertext Markup Language)
Used by Web programmers
Supports links to other documents, graphics, and audio and video files.
XML (Extensible Markup Language)
Enables programmers to capture specific types of data by creating their own elements
Not a replacement for HTML
XHTML (Extensible Hypertext Markup Language
Newer version of HTML that uses XML to produce Web pages that are easily accessible by newer portable devices.
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

31. A Guide to Programming Languages: One Size Doesn’t Fit All*
A Guide to Programming Languages: One Size Doesn’t Fit All
07/16/96
Markup languages (con’t.)
WML (Wireless Markup Language)enables developers to create pages for wireless devices
CSS (Cascading Style Sheets)defines the look and formatting of a Web page
World Wide Web Consortium (W3C)
International group—develops Web standards
Develops protocols and guidelines that ensure long-term growth for the Web
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

32. A Guide to Programming Languages: One Size Doesn’t Fit All*
A Guide to Programming Languages: One Size Doesn’t Fit All
07/16/96
Scripting languages
Create scripts—programs that control Web page actions or responses
VBScript
ActiveX controls
JavaScript
ECMAScript
AJAX
JSON
Used for serialization and transmitting structured data over a network
PHP
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

33. The Program Development Life Cycle*
The Program Development Life Cycle
07/16/96
Program development life cycle (PDLC)
Organized plan for managing the development of software
Consists of six phases, from problem definition through program implementation and maintenance
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

34. The Program Development Life Cycle*
07/16/96
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

35. The Program Development Life Cycle*
The Program Development Life Cycle
07/16/96
Phase 1: Defining the problem
Define the problem the program will solve
Define the program specifications, including decisions regarding data input, required processing, output, and the user interface
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

36. The Program Development Life Cycle*
The Program Development Life Cycle
07/16/96
Phase 2: Designing the program
Program design—identifies components of the program
Top-down program design—breaks program into small, manageable, highly focused routines
Procedures, functions, or subroutines
Structured design uses control structures—logical elements assembled in blocks of code that determine how subroutines will be programmed
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

37. The Program Development Life Cycle*
The Program Development Life Cycle
07/16/96
Phase 2: Designing the program (con’t.)
Basic control structures categories
Sequence control structure—code performed in line-by-line order
Selection control structure—also called a conditional or branch structure, this is a portion of code that leads to a block of code based on conditions being met
Case control structure—portion of code that branches to extensive conditional coding
Repetition control structure—also known as looping or iteration, this is a portion of code that repeats
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

38. The Program Development Life Cycle*
The Program Development Life Cycle
07/16/96
Phase 2: Designing the program (con’t.)
Algorithm
Combination of control structures
Step-by-step description of how to arrive at a solution
Nesting
Process of embedding control structures within one another
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

39. The Program Development Life Cycle*
07/16/96
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

40. The Program Development Life Cycle*
The Program Development Life Cycle
07/16/96
Phase 2: Designing the program (con’t.)
Program design tools
Structured charts—also called hierarchy charts, show top-down design of programs
Flowcharts—use diagrams to show the logic of a program
Unified Modeling Language (UML)—variation of flowcharting used to illustrate and document object-oriented systems during development
Pseudocode—uses a stylized form of writing to describe logic
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

41. The Program Development Life Cycle*
07/16/96
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

42. The Program Development Life Cycle*
The Program Development Life Cycle
07/16/96
Phase 3: Coding the program
Programmers convert algorithms into programming code
Syntax errors
Mistakes in the construction of the programming commands
Must be corrected for the program to run appropriately
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

43. The Program Development Life Cycle*
The Program Development Life Cycle
07/16/96
Phase 4: Testing and debugging the program
All errors, not just syntax errors, must be removed
Logic errors
Relate to problems in the solution’s design
Cause incorrect output
Program still runs despite logic errors
Syntax errors and logic errors—bugs
Debugging—process of eliminating errors
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

44. The Program Development Life Cycle*
The Program Development Life Cycle
07/16/96
Phase 5: Documenting the program
Documentation includes:
Overview of program functionality
Tutorials
Thorough explanation of main features
Reference documentation of program commands
Description of error messages
Program design work, including structure charts, pseudocode, and flowcharts
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

45. The Program Development Life Cycle*
The Program Development Life Cycle
07/16/96
Phase 6: Implementing and maintaining the program
Test the program
Have users work with the software
Correct errors
Program maintenance
Fix program errors discovered by users
Conduct periodic evaluations on a regular basis
Make modifications as needed to update the program or add features
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

46. Summary Explain what a programming language is and how it works.*
Summary
07/16/96
Explain what a programming language is and how it works.
Explain the development of programming languages over the years and the benefits and drawbacks of high-level programming languages.
Explain how object-oriented languages attempt to remedy the shortcomings of earlier languages.
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

47. *
Summary
07/16/96
List several popular object-oriented languages and explain their advantage over older languages.
List the six phases of the program development life cycle (PDLC) and explain why the PDLC is needed.
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

48. *
Summary
07/16/96
Explain why defining the problem in a top-down design manner leads to programs that are easier to debug and maintain.
Differentiate between problems that can arise in the testing and debugging phase as syntax and logic errors.
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall *

49. Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Printed in the United States of America.
Copyright © 2012 Pearson Education, Inc.  
Publishing as Prentice Hall
Copyright © 2012 Pearson Education, Inc. Publishing as Prentice Hall