Programming Languages What Is a Computer Program What

Programming Languages

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

The Software Development Life Cycle What is the software development life cycle (SDLC)? v Steps followed to build computer programs

Maintaining Defining and Understanding the problem Software Development Life Cycle Testing and Evaluating Planning and Designing Implementing

Categories of Programming Languages What are the categories of programming languages? assembly languages machine languages third-generation languages fourth-generation languages fifth-generation languages

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

Categories of Programming Languages What is machine language? v Only language computer understands directly v Each machine language instruction is represented by the computer as a series of binary digits

Each machine language instruction contains two parts, an operation code (opcode) and one or more operands. The majority of instructions require a single operand. The opcode identifies to the control unit what process is to be performed and the operand provides the data on which the process is to be performed. For example, on a Pentium machine the instruction 10100001 00000010 adds the decimal number 2 to the value currently in the accumulator. 10100001 is the opcode letting the control unit know to carry out an add to the accumulator and 00000010 is the decimal value 2 using 16 bit binary. For many operations the operand will be a memory address rather than the data itself.

What is assembly language? Categories of Programming Languages Assembler languages were the first attempt to make programming languages more human like. v Instructions made up of symbolic instruction codes v Programs written in an assembler language cannot be understood by the CPU. An assembler is required to translate the assembler code into machine language. v

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

Categories of Programming Languages What is a fourth-generation language (4 GL)? v Syntax is closer to human language than that of a 3 GL v SQL and report generator are examples v Nonprocedural language • Programmer specifies only what the program should accomplish; it Next does not p. 15. 19 Fig. 15 -22 explain how

Categories of Programming Languages What is a fifth-generation language (5 GL) ? v Provides visual or graphical interface for creating source code v Visual Basic. NET is an example Next p. 15. 20 Fig. 15 -25

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

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 Next p. 15. 18 Fig. 15 -21

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 Next p. 15. 20

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 Click to view Web Link v C++ is complete then click Object -Oriented object-oriented Programming Languages language Next p. 15. 21 event OOP term for message

Programming Languages What are the most widely used programming languages? v Hundreds of programming languages exist Java Visual Basic COBOL C BASIC Next p. 15. 22 C++ RPG

What is BASIC? v Designed Programming Languages for use as a simple, interactive problem-solving language v Beginner's All-purpose Symbolic Instruction Code Next p. 15. 22 Fig. 15 -24

Programming Languages What is Visual Basic? v Windows-based application that assists programmers in developing event-driven Windows-based applications Click to view Web Link then click Visual Basic Next p. 15. 22 Fig. 15 -25

What is COBOL? v Procedural Programming Languages 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

What is C? v Powerful Programming Languages language designed primarily to write system software Next p. 15. 25 Fig. 15 -27

What is C++? Programming Languages v Object-oriented programming language v Includes all elements of C language, plus additional features for working with object-oriented concepts Click to view Web Link then click C++ Next p. 15. 25 C# Called C Sharp Newer programming language that combines features of C and C++ Best suited for development of Web applications

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

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 application generators macros RAD tools: Visual Basic, Delphi, and Power. Builder

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

Web Page Program Development What Web page development tools are available? HTML Scripts, Applets, Servlets, and Active. X Controls Java, Java. Script, VBScript, and Perl Dynamic HTML XHTML, XML, and WML Web page authoring software

Web Page Program Development How does HTML code look?

Web Page Program Development How are special effects and forms added to a Web page? script Interpreted program that runs on client applet Also usually runs on client, but is compiled servlet Applet that runs on server Active. X 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 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 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? XHTML e. Xtensible HTML Includes features of HTML and XML e. Xtensible Markup Language WML Wireless Markup Language Allows Web page developers to create tags that describe data passed to a client so client, rather than server, can process data 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 Next p. 15. 38 Web services . NET-compliant smart clients Visual Studio. NET

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 Next p. 15. 38 Microsoft Front. Page Macromedia Dreamweaver Lotus Fast. Site Macromedia Flash Adobe Go. Live

Multimedia Program Development What is multimedia authoring software? v Combines text, graphics, animation, audio, and video interactive presentation v Also called authorware Next p. 15. 38 Toolbook Authorware Director

Multimedia Program Development How is multimedia authoring software used? Creates computerbased training (CBT) v CBT software called courseware v Distance learning, distance education, or online Next p. 15. 38 learning v Fig. 1540

Selecting a Programming Language or Program Development Tool What factors should be considered in selecting a programming language? Standards Interface Portability Next p. 15. 40 Suitability

Chapter 15 Complete