OLearyCECompleteChapter Programming and LanguagesPPT課件

1、14-1Competencies (Page 1 of 2) Describe the six steps of programming Discuss design tools including top-down design, pseudocode, flowcharts, and logic structures Describe program testing and the tools for finding and removing errors Page 4398第1頁(yè)/共27頁(yè)14-2Competencies (Page 2 of 2) Describe CASE tools

2、 and object-oriented software development Explain the five generations of programming languages Page 398第2頁(yè)/共27頁(yè)14-3Introduction In this chapter programming is described in two parts: (1) the steps in the programming process and (2) some of the programming languages available. Programming is part of

3、 Phase 4, systems development, in the systems life cycle. Competent end users need to understand the relationship between systems development and programming.Page 399第3頁(yè)/共27頁(yè)14-4Programs and Programming What is a Program? A problem-solving procedure A list of instructions Prewritten Custom-written A

4、pplication software System softwarePage 400第4頁(yè)/共27頁(yè)14-5What is Programming?Programming is software developmentSix step procedureProgram specificationProgram designProgram codeProgram testProgram documentationProgram maintenancePage 400第5頁(yè)/共27頁(yè)14-6Step 1: Program SpecificationPage 401Also called prog

5、rams definition or program analysis5 Step ProcessProgram ObjectivesDesired OutputInput DataProcessing RequirementsDocument Program Specifications第6頁(yè)/共27頁(yè)14-7Program Objectives Objectives are the problems that you are trying to solve Programming requires a clear statement of the problem that you are

6、looking to addressReturnPage 401第7頁(yè)/共27頁(yè)14-8Program Specification Steps ContinuedPage 402 Desired output Input Data Processing Requirements Program Specifications DocumentExample of statement of hours workedEnd users sketch of desired output第8頁(yè)/共27頁(yè)14-9Step 2: Program Design Plan a solution Use stru

7、ctured programming techniques Top-down program design Pseudocode Flowcharts Logic structuresPage 403第9頁(yè)/共27頁(yè)14-10Top-Down Program DesignPage 403Return第10頁(yè)/共27頁(yè)14-11PseudocodeProvides an outline of the logic and summary for a programPage 404Return第11頁(yè)/共27頁(yè)14-12FlowchartPage 404ReturnFlowchart symbols

8、Flowchart example第12頁(yè)/共27頁(yè)14-13Logic Structures Sequence structure Selection structure Loop structure Page 404第13頁(yè)/共27頁(yè)14-14Step 3: Program Code Writing the program or coding The good program Reliable Catch input errors Understandable to other programmers Structured programs best method Use the most

9、 appropriate computer language CodingPage 407第14頁(yè)/共27頁(yè)14-15Coding Formatting or presentation language Programming languagePage 408第15頁(yè)/共27頁(yè)14-16Step 4: Program Test Debugging Testing Eliminating errors Syntax errors Logic errors Testing processPage 422第16頁(yè)/共27頁(yè)14-17Step 5: Program Documentation Writ

10、ten descriptions and procedures about a program Important for people who will use the program Users Operators ProgrammersPage 411第17頁(yè)/共27頁(yè)14-18Step 6: Program Maintenance 75% of total lifetime cost Error-free operations Effective program Two categories Operations Changing needs Page 412第18頁(yè)/共27頁(yè)14-1

11、9Case Tools Computer-aided software engineering (CASE) Automate development process Designing Coding Testing activitiesPage 414第19頁(yè)/共27頁(yè)14-20Object-Oriented Software Development Focuses less on procedures, more on relationship between objects OOP: Object-oriented programming Object contains both the

12、 data and the processing operations Page 415第20頁(yè)/共27頁(yè)14-21Generations of Programming Languages (Page 1 of 2) Occurring in “generations” or “l(fā)evels” Levels-Machine languages to natural languages There are five generations : Lower level closer to machine language Higher level closer to human-like lang

13、uagePage 415第21頁(yè)/共27頁(yè)14-22 1st - Machine languages 2nd - Assembly languages 3rd - High level procedural languages (3GL) 4th - Problem-Oriented languages (4GL) 5th - Natural Languages & Visual programming languages (5GL)Page 415Generations of Programming Languages (Page 2 of 2)第22頁(yè)/共27頁(yè)14-23Caree

14、rs In IT Computer programmers create, test, and troubleshoot programs Responsibility may also include updating and repairing existing programs Employers seek individuals with a bachelors degree in computer science or information systems but there are positions available for those with a two-year deg

15、ree Desired traits include patience, logical thinking, and attention to detail Computer Programmers can expect to earn $48K - $81K annuallyPage 418第23頁(yè)/共27頁(yè)14-24A Look to the FutureMI-Tech Synapse Solutions has created a system called MI-tech Understands word order and meaning Computer translates wi

16、sh list into machine language Page 419第24頁(yè)/共27頁(yè)14-25Discussion Questions (Page 1 of 2) Identify and discuss each of the six steps of programming. Describe CASE tools and OOP. How does CASE assist programmers? What is meant by “generation” in reference to programming languages? What is the difference between low-level and high-l