Computers Are Your FutureSlide 2What You Will Learn AboutSlide 4Programming LanguagesDevelopment of Programming LanguagesFirst-Generation LanguagesSecond-Generation LanguagesThird-Generation LanguagesThird-Generation Languages (continued)Slide 12Slide 13Fourth-Generation LanguagesObject-Oriented ProgrammingObjectsCommon Business-Oriented Language (COBOL)Formula Translator (Fortran)AdaBeginner’s All-Purpose Symbolic Instruction Code (BASIC)Visual Basic (VB)PascalCSmalltalkC++JavaSlide 27Sample Java ProgramWeb-Based LanguagesThe Program Development Life Cycle (PDLC)Phase 1: Defining the ProblemPhase 2: Designing the ProgramPhase 3: Coding the ProgramPhase 4: Testing and Debugging the ProgramPhase 5: Formalizing the SolutionPhase 6: Implementing and Maintaining the ProgramChapter 11 SummaryChapter 11 Summary, continuedComputers Are Your Future© 2006 Prentice Hall, Inc.© 2006 Prentice Hall, Inc. Slide 2Computers Are Your Future: Chapter 11Computers Are Your FutureChapter 11Programming Languages and Program Development© 2006 Prentice Hall, Inc. Slide 3Computers Are Your Future: Chapter 11What You Will Learn AboutWhat a programming language isMachine language and assembly languageHigh-level programming languages The shortcomings of early languagesPopular programming languages© 2006 Prentice Hall, Inc. Slide 4Computers Are Your Future: Chapter 11What You Will Learn AboutThe six phases of the program development life cycle (PDLC) Why top-down programming makes programs easier to debug and maintainThe three basic types of control structuresSyntax errors and logic errors in programs© 2006 Prentice Hall, Inc. Slide 5Computers Are Your Future: Chapter 11Machine LanguageAdaPascalFortranCOBOLAssembly LanguageSmalltalkVisual BasicBASICJavaC and C++Programming LanguagesProgramming languages are artificial languages created to tell the computer what to doThey consist of vocabulary and a set of rules to write programsThe program development life cycle (PDLC) is an organized method of software development© 2006 Prentice Hall, Inc. Slide 6Computers Are Your Future: Chapter 11Development of Programming LanguagesProgramming languages are classified by levels or generationsLower-level languages are the oldestThe five generations of programming languages are:Machine languagesAssembly languagesProcedural languagesProblem-oriented languagesNatural languages© 2006 Prentice Hall, Inc. Slide 7Computers Are Your Future: Chapter 11First-Generation LanguagesMachine language: Consists of binary numbers (0s and 1s)Is the earliest programming languageIs the only language the computer understands without translationIs machine dependentEach family of processors has its own machine language© 2006 Prentice Hall, Inc. Slide 8Computers Are Your Future: Chapter 11Second-Generation LanguagesAssembly language: Resembles machine language Is a low-level languageUses brief abbreviations for program instructions.Abbreviations are called mnemonicsA program is written in source code (text file) and translated into machine language by an assembler© 2006 Prentice Hall, Inc. Slide 9Computers Are Your Future: Chapter 11Third-Generation LanguagesProcedural languages: Are high-level languages that tell the computer what to do and how to do itCreate programs at a high level of abstractionAre easier to read, write, and maintain than machine and assembly languagesUse a compiler or interpreter to translate codeFortran and COBOL are third-generation languages© 2006 Prentice Hall, Inc. Slide 11Computers Are Your Future: Chapter 11Third-Generation Languages (continued)Spaghetti Code and the Great Software Crisis:GOTO statements resulted in programs that were difficult to followThis problem led to the software crisis of the 1960sPrograms were not ready on timePrograms exceeded their budgetsPrograms contained too many errorsCustomers were not satisfied© 2006 Prentice Hall, Inc. Slide 12Computers Are Your Future: Chapter 11Third-Generation Languages (continued)Structured programming languages:Were developed to improve software developmentInclude Algol and PascalForbid the use of GOTO statementsUse control structures IF-THEN-ELSE© 2006 Prentice Hall, Inc. Slide 13Computers Are Your Future: Chapter 11Third-Generation Languages (continued)Modular programming languages:Were developed because of problems in structured programming languagesAre used to create programs that are divided into separate modulesEach module carries out a special functionRequire specified input to produce specified output© 2006 Prentice Hall, Inc. Slide 14Computers Are Your Future: Chapter 11Fourth-Generation LanguagesTypes of fourth-generation languages include:Report generators Languages for printing database reportsQuery languagesLanguages for getting information out of databasesFourth-generation languages are nonproceduralThey do not force programmers to follow procedures to produce results© 2006 Prentice Hall, Inc. Slide 15Computers Are Your Future: Chapter 11Object-Oriented ProgrammingObject-oriented programming (OOP): Relies on component reusabilityThe ability to produce program modules that perform a specific taskEliminates the distinction between programs and dataUses objects that contain data and procedures© 2006 Prentice Hall, Inc. Slide 16Computers Are Your Future: Chapter 11ObjectsObjects are units of information that contain data as well as methods that process and manipulate the data Classes of objects:Hierarchy or category of objectsObjects at the top of the category are broader in scope than the subclass objectsInheritance refers to an object’s capacity to “pass on” its characteristics to its subclasses© 2006 Prentice Hall, Inc. Slide 17Computers Are Your Future: Chapter 11Sample Cobol programCommon Business-Oriented Language (COBOL)COBOL:The earliest (1959) high-level languageThe most widely used business languageA proven way to do accounting, inventory, billing, and payrollRequires programmers to explain what the program is doing at each step© 2006 Prentice Hall, Inc. Slide 18Computers Are Your Future: Chapter 11Sample Fortran programFormula Translator (Fortran)Fortran: Began in the 1950sIs suited to scientific, mathematical, and engineering applicationsIs used to solve complex