Chapter 13 Programming Languages and Program Development

Chapter 13 Objectives Next Describe various ways to develop Web pages including HTML, scripting languages, DHTML, XML, WML, and Web page authoring software Differentiate between machine and assembly languages Identify and discuss the purpose of procedural programming languages Discuss the advantages and uses of visual programming languages Identify and discuss the characteristics of object-oriented programming languages Identify the uses of various nonprocedural languages and tools Identify the uses of popular multimedia authoring programs List the six steps in the program development cycle Differentiate between structured design and object-oriented design Explain the basic control structures used in designing solutions to programming problems

Computer Programs and Programming Languages What is a computer program? p Fig Next  Set of instructions that directs computer to perform tasks  Programming language—used to write instructions Click to view videoClick to view animation

Computer Programs and Programming Languages What are low-level languages and high-level languages? p Next High-level language Low-level language Machine-dependent runs only on one type of computer Often machine-independent can run on many different types of computers Machine and assembly languages are low-level

Low-Level Languages What is machine language? p Fig Next  Only language computer directly recognizes Click to view animation

Low-Level Languages What is assembly language? p Fig Next  Instructions made up of symbolic instruction codes, meaningful abbreviations and codes  Source program contains code to be converted to machine language

Procedural Languages What is a procedural language? p Next Most widely used are BASIC, COBOL, and C Uses series of English-like words to write instructions third-generation language (3GL) Often called third-generation language (3GL) Programmer assigns name to sequence of instructions that tells computer what to accomplish and how to do it Click to view animation

Procedural Languages What is a compiler? p Fig Next  Program that converts entire source program into machine language before executing it

Procedural Languages What is an interpreter? p Fig Next  Program that translates and executes one program code statement at a time  Does not produce object program

Procedural Languages What is BASIC? p Fig Next  Designed for use as simple, interactive problem-solving language  Beginner’s All-purpose Symbolic Instruction Code

Procedural Languages What is COBOL? p Fig Next Click to view Web Link, then click COBOL below Chapter 13  Designed for business applications  English-like statements make code easy to read, write, and maintain  COmmon Business-Oriented Language

Procedural Languages What is C? p Fig Next  Powerful language originally designed to write system software  Requires professional programming skills

Object-Oriented Programming Languages What is an object-oriented programming (OOP) language? p Next Used to implement object-oriented design Major benefit is ability to reuse existing objects Event-driven— checks for and responds to set of events C++ and Java are complete object-oriented languages Object is item that contains data and procedures that act on data Event is action to which program responds

Object-Oriented Programming Languages What is C++? p Fig Next Click to view Web Link, then click C++ below Chapter 13  Includes all elements of C, plus additional features for working with object-oriented concepts  Used to develop database and Web applications

Object-Oriented Programming Languages What is Java? p Fig Next Click to view Web Link, then click Java below Chapter 13  Developed by Sun Microsystems  Similar to C++ but uses just-in-time (JIT) compiler to convert source code into machine code Click to view video

Object-Oriented Programming Languages What is a visual programming language? p Next Click to view Web Link, then click RAD below Chapter 13 Programmer writes and implements program in segments Visual programming environment (VPE) allows developers to drag and drop objects to build programs Often used in RAD (rapid application development) environment Sometimes called fifth-generation language Provides visual or graphical interface for creating source code

Object-Oriented Programming Languages What is Visual Studio.NET? p Next Click to view Web Link, then click Visual Studio.NET below Chapter 13  Suite of visual programming languages and RAD tools .NET is set of technologies that allows program to run on Internet  Visual Basic.NET is used to build complex object-based programs Step 1. The programmer designs the user interface. Step 2. The programmer assigns properties to each object on the form. Step 3. The programmer writes code to define the action of each command button. Step 4. The programmer tests the application.

Object-Oriented Programming Languages What is Delphi? p Fig Next  Powerful visual programming tool  Ideal for large-scale enterprise and Web applications

Object-Oriented Programming Languages What is PowerBuilder? p Fig Next  Another powerful visual programming tool  Best suited for Web-based and large-scale object-oriented applications

Nonprocedural Languages What is RPG (Report Program Generator)? p Fig Next  Nonprocedural language used for generating reports, performing computations, and updating files  Nonprocedural language—contains English-like instructions that retrieve data

Nonprocedural Languages What is a fourth-generation language (4GL)? p Fig Next  Nonprocedural language that allows access to data in database  Popular 4GL is SQL, query language that allows users to manage data in relational DBMS

Program Development Tools What is an application generator? p Fig Next  Program that creates source code or machine code from specification  Consists of report writer, form, and menu generator  Form provides areas for entering data

Program Development Tools What is Visual Basic for Applications (VBA)? p Fig Next Click to view Web Link, then click Macros below Chapter 13  Macro programming language  Macro—series of statements used to automate tasks

Web Page Development What is HTML (Hypertext Markup Language)? p Fig Next Click to view Web Link, then click HTML below Chapter 13  Used to create Web pages

Web Page Development How are special effects and interactive elements added to a Web page? p Next Counter Counter tracks number of visitors to Web site Image map Image map graphic image that points to URL Script Script interpreted program that runs on client Applet Applet usually runs on client, but is compiled Processing form Processing form collects data from visitors to Web site Servlet Servlet applet that runs on server ActiveX control ActiveX control small program that runs on client

Web Page Development What is the common gateway interface (CGI)? p Next  Communications standard that defines how Web server communicates with outside sources Step 3. When the user submits a request, it is sent to the CGI program. The CGI program contacts the database and requests information for the user. In this case, it looks for a movie titled The Secret Garden. Step 1. The programmer stores the CGI program in a special folder on the Web server such as /cgi-bin. Step 2. The Webmaster creates a link between the CGI program and Web page. When a user displays the Web page, the CGI program automatically starts. Step 4. The CGI program receives information from the database, assembles it in an HTML format, and sends it to the user’s Web browser. Database  CGI script—program that manages sending and receiving across CGI

Web Page Development What is a scripting language? p Fig Next Click to view Web Link, then click Scripting Languages below Chapter 13  Typically easy to learn and use  JavaScript—adds dynamic content and interactive elements to Web page  VBScript (Visual Basic, Scripting Edition)—adds intelligence and interactivity to Web page  Perl (Practical Extraction and Report Language)— has powerful text processing capabilities

Web Page Development What is dynamic HTML (DHTML)? p Fig Next  Allows developers to include more graphical interest and interactivity in Web page

Web Page Development What are XHTML, XML, and WML? p Next Click to view Web Link, then click XML below Chapter 13 XHTML (Extensible HTML) enables Web sites to be displayed more easily on microbrowsers XML (Extensible Markup Language) allows developers to create customized tags WML (Wireless Markup Language) allows developers to design pages specifically for microbrowsers Includes features of HTML and XML Uses wireless application protocol (WAP), standard that specifies how wireless devices communicate with Web Server sends entire record to client, enabling client to do much of processing without going back to server

Microsoft FrontPage Macromedia Flash Web Page Development Macromedia Fireworks What is Web page authoring software? p Next  Creates sophisticated Web pages without using HTML  Generates HTML Macromedia Dreamweaver Lotus FastSite Adobe LiveMotion Adobe GoLive

Multimedia Program Development What is multimedia authoring software? p Fig Next  Combines text, graphics, animation, audio, and video into interactive presentation  Used for computer- based training (CBT) and Web-based training (WBT)  Software includes Toolbook, Authorware, and Director

Other Programming Languages What are other available programming languages? p Next ALGOLALGOLADAADAAPLAPL FORTHFORTHLISPLISPHYPERTALKHYPERTALKFORTRANFORTRAN LOGOLOGOPASCALPASCALMODULA-2MODULA-2 PILOTPILOTSMALLTALKSMALLTALKPROLOGPROLOGPL/IPL/I

The Program Development Cycle What is the program development cycle? p Fig Next  Steps programmers use to build computer programs  Programming team—Group of programmers working on program

Step 1 — Analyze Requirements What is involved in analyzing the requirements? p Fig Next 1. Review requirements 2. Meet with systems analyst and users 3. Identify input, output, processing, and data components  IPO chart— Identifies program’s inputs, outputs, and processing steps IPO chart

Programmer begins with general design and moves toward detailed design Step 2 — Design Solution What is involved in designing the solution? p Next Object-oriented design Structured design, sometimes called top-down design Two approaches Devise solution algorithm, step-by-step procedure to solve problem

Step 2 — Design Solution What is a hierarchy chart? p Fig Next  Shows program modules graphically  Also called structure chart

Step 2 — Design Solution What is object-oriented (OO) design? p Fig Next Click to view Web Link, then click Object-Oriented Design below Chapter 13  Programmer packages data and procedure into single unit, an object  Objects are grouped into classes  Class diagram represents hierarchical relationships of classes graphically

Step 2 — Design Solution What is a sequence control structure? p Fig Next  Control structure that shows actions following each other in order  Control structure depicts logical order of program instructions

Step 2 — Design Solution What is a selection control structure? p Fig Next  Tells program which action to take, based on a certain condition  Two types  Case control structure  If-then-else control structure—yields one of two possibilities: true or false

Step 2 — Design Solution What is a case control structure? p Fig Next  Yields one of three or more possibilities

Step 2 — Design Solution What is a repetition control structure? p Figs –13-33 Next  Enables program to perform one or more actions repeatedly  Do-while control structure—repeats as long as condition is true  Do-until control structure—repeats until condition is true Do-While Control StructureDo-Until Control Structure

Step 2 — Design Solution What is a program flowchart? p Fig Next  Graphically shows logic in solution algorithm

Step 2 — Design Solution What is an example of a flowchart? p Fig Next

Step 2 — Design Solution What is flowcharting software? p Fig Next Click to view Web Link, then click Flowcharting Software below Chapter 13  Used by programmers to develop flowcharts

Step 2 — Design Solution What is pseudocode? p Fig Next  Uses condensed form of English to convey program logic

Step 3 — Validate Design What is involved in validating the design? p Next Check program design for accuracy Logic error design flaw that causes inaccurate results Test data sample data that mimics real data that program will process Programmer checks logic for correctness and attempts to uncover logic errors Desk check programmers use test data to step through logic Structured walkthrough programmer explains logic of algorithm while programming team steps through program logic

Step 4 — Implement Design What is implementation? p Fig Next Click to view Web Link, then click Extreme Programming below Chapter 13  Writing the code that translates the design into a program  Syntax—rules that specify how to write instructions  Comments—program documentation  Extreme programming (XP)—coding and testing as soon as requirements are defined

Step 5 — Test Solution What is involved in testing the solution? p Next Ensure program runs correctly and is error free Debugging—locating and correcting syntax and logic errors, or bugs Test copy of program, called beta, sometimes used to find bugs

Step 6 — Document Solution What is involved in documenting the solution? p Next  Programmer performs two activities Reviews program code—removes dead code, program instructions that program never executes Reviews documentation

Summary of Programming Languages and Program Development Various programming languages used to write and develop computer programs The program development cycle and the tools used to make this process efficient Web development and multimedia development tools Chapter 13 Complete