Chapter 15 Program Development and Programming Languages

Explain the six steps in the program development life cycle Describe top-down program design Explain structured program design and the three basic control structures Explain the differences among the categories of programming languages Describe the object-oriented approach to program development Identify programming languages commonly used today Identify the uses of application generators, macros, and RAD tools Describe various Web page development tools, including HTML, DHTML, XML, and WML Identify uses of multimedia authoring packages Chapter 15 Objectives Next p.15.2

programming language Set of words, symbols, and codes that enables a programmer to communicate instructions to a computer What Is a Computer Program? What is a computer program? v Set of instructions that directs computer to perform tasks p.15.2 Next

The Program Development Life Cycle What is the program development life cycle (PDLC)? v Steps followed to build computer programs p Fig Next

The Program Development Life Cycle How is program development related to system development? v Program development is ongoing process within system development p.15.3 Fig Next

Step 1 – Analyze Problem What is involved in analyzing the problem? p.15.4 Next Review program specifications package Meet with systems analyst and users Identify each program’s input, output, and processing components

Step 1 – Analyze Problem What is an IPO chart? v Identifies program’s inputs, outputs, and processing steps v Used to establish design specifications p.15.4 Fig Next

structured design Focuses on how to build program based on requirements Step 2 – Design Programs p.15.5 Next top-down design Focuses on what program should do What is involved in designing programs?

Step 2 – Design Programs What is a hierarchy chart? v Used to show program modules graphically v Also called structure chart or top-down chart p.15. 6Fig Next

Step 2 – Design Programs What is structured design? v Technique that builds all program logic from combination of three basic control structures p.15.6 Next Click to view Web Link then click Structured Design sequence control structure selection control structure repetition control structure

Step 2 – Design Programs What is a sequence control structure? v Shows one or more actions following each other in order v Actions could be Inputs Processes Outputs p.15.7 Fig Next

Step 2 – Design Programs What is a selection control structure? v Tells program which action to take, based on a certain condition p.15.7 Next if-then-else control structure case control structure

Step 2 – Design Programs What is an if-then-else control structure? Next p.15.7 Fig. 15-6

Step 2 – Design Programs What is a case control structure? Next p.15.7 Fig. 15-7

Step 2 – Design Programs What is a repetition control structure? v Used when program performs one or more actions repeatedly as long as certain condition is met p.15.8 Next do-while control structure do-until control structure

Step 2 – Design Programs What is a do-while control structure? v Repeats one or more times as long as condition is true p.15.8 Fig Next

Step 2 – Design Programs What is a do-until control structure? v Tests condition at end of loop p.15.8 Fig Next

Step 2 – Design Programs v No dead code v No infinite loops v One entry point v One exit point p.15.8 Next dead code Any code, or program instruction, that program never executes infinite loop Set of instructions that repeats continuously entry point Location where program, module, or control structure begins exit point Location where it ends What is a proper program?

Step 2 – Design Programs How are entry and exit points shown? v Each control structure should have one entry point and one exit point p.15.9 Fig Next

Step 2 – Design Programs What is a program flowchart? v Graphically shows logic in a solution algorithm Next p Fig

Step 2 – Design Programs What is a Nassi-Schneiderman (N-S) chart? v Graphically shows logic in a solution algorithm p Fig Next

Step 2 – Design Programs What is pseudocode? v Uses condensed form of English to convey program logic p Fig Next

Step 2 – Design Programs What is a quality review? v Review of program design Desk check Structured walkthrough p.1512 Next logic error Design flaw that causes inaccurate results

Step 3 – Code Programs What is involved in coding programs? v Two steps Translating solution algorithm into a programming language Entering programming language code into the computer p Fig Next

Step 4 – Test Programs What is involved in testing programs? v Goal is to ensure program runs correctly and is error free v Three types of errors Syntax Logic Run time p Next

Step 4 – Test Programs What is debugging? v Process of locating and correcting syntax and logic errors in program p Fig Next

Step 5 – Formalize Solution What is involved in formalizing a solution? v Programmer performs two activities Reviews program code Reviews documentation p Next

Step 6 – Maintain Programs What is involved in maintaining programs? v Two activities Identify errors Identify enhancements –Involves modifying existing programs to improve their functionality p Next

machine languages Categories of Programming Languages What are the categories of programming languages? p Next Click to view video Click to view animation assembly languages third-generation languages fourth-generation languages fifth-generation languages

Machine and assembly languages are low-level Categories of Programming Languages What are low- and high-level programming languages? p Next Machine-dependent language Runs only on one particular computer low-level language Programming language that is machine-dependent Third-generation, fourth- generation, and fifth-generation languages are high-level Machine-independent language Can run on many different types of computers high-level language Language that is machine- independent

Categories of Programming Languages What is machine language? v Only language computer understands directly p Fig Next Click to view animation

Categories of Programming Languages What is assembly language? v Instructions made up of symbolic instruction codes Next p Fig

Categories of Programming Languages What is a third-generation language (3GL)? v Uses a series of English-like words to write instructions v Procedural language Requires program instructions to tell computer what to accomplish and how to do it p Fig Next Click to view animation

Categories of Programming Languages What is a compiler? v Program that converts entire source program into machine language before executing it p Fig Next

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

Categories of Programming Languages What is a fourth-generation language (4GL)? v Syntax is closer to human language than that of a 3GL v SQL and report generator are examples p Fig Next v Nonprocedural language Programmer specifies only what the program should accomplish; it does not explain how

Categories of Programming Languages What is a fifth-generation language (5GL) ? p Fig Next v Provides visual or graphical interface for creating source code v Visual Basic.NET is an example

Object-Oriented Program Development What is the object-oriented (OO) approach? v Programmer can package data and program (or procedure) into a single unit, called an object v Class is larger category of objects p Next

Object-Oriented Program Development What is an object-oriented programming (OOP) language? v Language that uses the OO approach v OOP is event-driven Checks for and responds to set of events v C++ is complete object-oriented language p Next Click to view Web Link then click Object- Oriented Programming Languages event OOP term for message

Programming Languages What are the most widely used programming languages? v Hundreds of programming languages exist p Next Java Visual BasicCOBOLCC++ RPG BASIC

Programming Languages What is BASIC? v Designed for use as a simple, interactive problem-solving language v Beginner's All-purpose Symbolic Instruction Code p Fig Next

Programming Languages What is Visual Basic? v Windows-based application that assists programmers in developing event-driven Windows-based applications p Fig Next Click to view Web Link then click Visual Basic

Programming Languages What is COBOL? v Procedural language with English-like statements that make it easy to read, write, and maintain v Common Business -Oriented Language v 70 billion lines of code exist p Fig Next

Programming Languages What is C? v Powerful language designed primarily to write system software p Fig Next

Programming Languages What is C++? v Object-oriented programming language v Includes all elements of C language, plus additional features for working with object-oriented concepts p Next Click to view Web Link then click C++ C# Called C Sharp Newer programming language that combines features of C and C++ Best suited for development of Web applications

Programming Languages What is RPG? v Easy-to-write nonprocedural language used primarily in small businesses v Report Program Generator p Fig Next

RAD tools: Visual Basic, Delphi, and PowerBuilder Program Development Tools What are program development tools? v User-friendly software products designed to help both program developers and nontechnical users create solutions to information requirements p Next macrosapplication generators

VBA macro used to automate an auto loan computation Program Development Tools What is Visual Basic for Applications (VBA)? v Used to write own macros in Word, Excel, Access, and PowerPoint v Use objects, classes, and other object- oriented concepts p Fig Next Macro dialog box Loan Data button Macro dialog box in Excel window guiding user through the data entry process

Web Page Program Development p Next HTML Scripts, Applets, Servlets, and ActiveX Controls Java, JavaScript, VBScript, and Perl Dynamic HTML XHTML, XML, and WML Web page authoring software What Web page development tools are available?

Web Page Program Development How does HTML code look? p Fig Next

Web Page Program Development How are special effects and forms added to a Web page? p Next script Interpreted program that runs on client applet Also usually runs on client, but is compiled servlet Applet that runs on server ActiveX control Small program that runs on client

Web Page Program Development What is the common gateway interface (CGI)? v Communications standard that defines how Web server communicates with clients p Next Click to view Web Link then click CGI Programs CGI script Program that manages sending and receiving between Web server and client

Web Page Program Development What is dynamic HTML (DHTML)? v Allows you to include more graphical interest and interactivity on Web page p Fig Next Click to view Web Link then click Dynamic HTML When you point to Recreational Vehicles link, image to right is a camper and text discusses communication from your RV When you point to Rural Regions link, image to the right is a farmer and text discusses calling from farm

Web Page Program Development What are XML, XHTML, and WML? p Next Click to view Web Link then click WML XHTML eXtensible HTML Includes features of HTML and XML XML eXtensible Markup Language Allows Web page developers to create tags that describe data passed to a client so client, rather than server, can process data WML Wireless Markup Language Allows Web page developers to design pages specifically for microbrowsers Uses the wireless application protocol (WAP)

Web Page Program Development What is the.NET Platform? v Environment for developing and running applications v Allows for creation and running of Web services p Next Web services.NET-compliant smart clients Visual Studio.NET

Microsoft FrontPage Web Page Program Development What is Web page authoring software? v Creates sophisticated Web pages using a tool that is much easier to use than HTML v Generates HTML p Next Macromedia Dreamweaver Lotus FastSiteMacromedia Flash Adobe GoLive

Multimedia Program Development What is multimedia authoring software? v Combines text, graphics, animation, audio, and video into interactive presentation v Also called authorware p Next ToolbookAuthorwareDirector

Multimedia Program Development How is multimedia authoring software used? v Creates computer- based training (CBT) v CBT software called courseware v Distance learning, distance education, or online learning p Fig Next

Standards Portability Suitability Interface Selecting a Programming Language or Program Development Tool p Next What factors should be considered in selecting a programming language?

Summary of Program Development and Programming Languages v What is a computer program? v The program development life cycle v Object-oriented program development v Programming languages v Program development tools v Web page program development v Multimedia program development v Selecting a programming language Chapter 15 Complete