1 Program Flow Charting How to tackle the beginning stage a program design

2 A Program Set of instructions written in a programming language that tells the computer what to do

3 Programmers Prepare instructions that make up the programPrepare instructions that make up the program Run the instructions to see if they produce the correct resultsRun the instructions to see if they produce the correct results Make correctionsMake corrections Document the programDocument the program Interact withInteract with –Users –Managers –Systems analysts Coordinate with other programmers to build a complete systemCoordinate with other programmers to build a complete system

4 The Programming Process Defining the problemDefining the problem Planning the solutionPlanning the solution Coding the programCoding the program Testing the programTesting the program Documenting the programDocumenting the program

5 The Programming Process: Defining the Problem What is the inputWhat is the input What output do you expectWhat output do you expect How do you get from the input to the outputHow do you get from the input to the output

6 The Programming Process: Planning the Solution AlgorithmsAlgorithms –Detailed solutions to a given problem Sorting records, adding sums of numbers, etc.. Design toolsDesign tools –Flowchart –Pseudocode Has logic structure, but no command syntax

7 Desk-checkingDesk-checking –Personal code design walk through Peer ReviewsPeer Reviews –“Code walk through”/structured walk through The Programming Process: Planning the Solution

8 The Origin of the Algorithm From “The Cartoon Guide to Computer Science,” by Larry GonickFrom “The Cartoon Guide to Computer Science,” by Larry Gonick

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12 The Indian Numerals

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19 What defines an algorithm

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23 Flow Control Elements The Programming Process: Planning the Solution

24 Needed Elements Start/Stop Process Decision Input/Output Connector

25 The Programming Process: Planning the Solution Accept series of numbers and display the average

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28 The Programming Process: Coding the Program Translate algorithm into a formal programming languageTranslate algorithm into a formal programming language Within syntax of the languageWithin syntax of the language How to key in the statements?How to key in the statements? –Text editor –Programming environment Interactive Development Environment (IDE)

29 The Programming Process: Testing the Program Translation – compilerTranslation – compiler –Translates from source module into object module –Detects syntax errors Link – linkage editor (linker)Link – linkage editor (linker) –Combines object module with libraries to create load module –Finds undefined external references DebuggingDebugging –Run using data that tests all statements –Logic errors

30 The Programming Process: Documenting the Program Performed throughout the developmentPerformed throughout the development Material generated during each stepMaterial generated during each step –Problem definitions –Program plan –Comments within source code –Testing procedures –Narrative –Layouts of input and output –Program listing

31 1 st Generation: Machine Level1 st Generation: Machine Level 2 nd Generation: Assembly Level2 nd Generation: Assembly Level 3 rd Generation: High Level3 rd Generation: High Level Procedural Level Languages

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36 FORTRAN Third Generation Languages

37 COBOL Third Generation Languages

38 BASIC Third Generation Languages

39 Third Generation Languages C++

40 Questions?

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