bab 1 - introductory concepts

8/3/2019 Bab 1 - Introductory Concepts

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Course Lecturer:Pn Norhayati bt Jais

Correction and rewrite:

Norzaiwin B Zainal Abidin


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Define programme, programmer andprogramming language

Types of programming language

Types of programming: Structured programming

Modular programming

Object-oriented programming


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List stages involved in problem solving

Elements of problem analysis : Input, Process,Output

Design tools for problem solving: Flowchart

Pseudo code

IPO Chart (Input-Process-Output Chart)

Types of error in programming: syntax error,

run-time error & logical error


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ProgrammeProgrammeProgrammeProgramme - A set of instructions that tells

the computer what to do ProgrammerProgrammerProgrammerProgrammer A person who is involved in

the programming phases.

Programming languageProgramming languageProgramming languageProgramming language is the languageunderstood by the computer, used to tellthe computer what to do.


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Machine languagesMachine languagesMachine languagesMachine languages is a true computer language

machine specific instructions, consists of binarynumbers i.e 0 and 1.

lowest level representation of computer program

Assembly languagesAssembly languagesAssembly languagesAssembly languages

Using mnemonics to represent machine languageinstructions (translated via assemblers)

Example:mov ax, 1234h (mov value 1234h intoregister ax)

HighHighHighHigh----level languageslevel languageslevel languageslevel languages Codes similar to everyday English

Use mathematical notations (translated via compilers)

Example: grossPay = basePay + overTimePay


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Structured Programming

Computer programming in which the statements are organized in aspecific manner to minimize error or misinterpretation.ALGOL, Pascal, C, PL/I andALGOL, Pascal, C, PL/I andALGOL, Pascal, C, PL/I andALGOL, Pascal, C, PL/I and AdaAdaAdaAda....

Functional / Modular Programming

Modular programming is subdividing program into separatesubprograms such as functions and subroutines. make programshorter, hence easier to read and understand.

Scheme, LISPScheme, LISPScheme, LISPScheme, LISP Object Oriented Programming (OOP)

A computer programming methodology that focuses on datarather than processes, with programs composed of self-sufficientmodules (objects) containing all the information needed to

manipulate a data structure. Abbreviated OOP.Java, C++Java, C++Java, C++Java, C++


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Problem requirements

Problem Analysis Program Design (Algorithm)

Writing Programme

Testing and debugging Documentation


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Before any problem can solve, we

really have to understand what isto be solve.

To understand, we should thinkand ask question

1. Problem Requirements


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All computer programs have several

elements in common. Input

Process

Output

They receive data input from users, storethe data on some storage device (e.g. harddisk), process the data into useful

information, and finally produce output inthe form of reports. (Figure 1)

2. Problem Analysis


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S T O R A G E

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Identify and understand the problem to be

solved. Problem analysis is done by determining 3

main things: InputInputInputInput needed

OutputOutputOutputOutput has to be produced

ProcessProcessProcessProcess to be carried out in order to get the outputbased on the input

INPUTINPUT OUTPUTOUTPUTPROCESS

(programme)PROCESS

(programme)

2. Problem Analysis


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Better known as Algorithm

Algorithm is a list of sequential steps tosolve a problem

2 methods in writing algorithm :

Pseudo Code

steps in problem solving (logic)written using a combination of spoken languageand some programming language semiformal.

Flow Chart steps in problem solving (logic)

using diagrams and specific symbols.


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Pseudo Code steps in problem solving (logic)written using a combination of spoken language

and some programming language semiformal. Example:

Begin

Read aRead b

Count y=a*bWrite y

End

** PSEUDO CODEPSEUDO CODE


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**** Flow Chart SymbolsBEGIN / END

PROCESS

INPUT / OUTPUT

DECISION

CONTINUE

ACTIVITY FLOW


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Implementation phase, where the code iswritten and typed using the computer

A logic problem solving represented bypseudo codes dan flow chart converted tocomputer programme, using suitable

language

Language example: C, C++, Visual Basic,Java, PHP


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Program that have been complete, has to beteated/runto make sure the output iscorrect.

Debugging that is by inserting true data tobe tested

If there is an error, correct it, depend onwhich error.


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There tree types of error.

Logical Error due to ways of solving andsteps is not correct and the flow is not logic. Syntax Error due to syntax statement is

not correct according to program language

used. Run-time Error due to input data is not the

input of the program required.


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This the last steps, preparing a report for

future upgrading and correction. Document consists: Types of problem or a true specific requirement Types of input, output, constraint and formula

for the problem. Logic algorithm used such as flow chart or

pseudo code Example of output executed using test data. Steps or guidance of using a program


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Define & Analyst Problemo Define & knowing problems

o

Define data problems

input & output

Program Design

o Plan & fixed strategyo Knows data model,

component & relation

o Build algorithm/ flowchart

Code the programTranslate the algorithm into

program code using the

specific programming

language

Test Programo Test the program using

computer for errors.

o Correct output as define by

user.

Prepare documentationo Problem analysis document

and program and modules

involve

CorrectProgram

Error


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THE PROBLEMTHE PROBLEMTHE PROBLEMTHE PROBLEMA durian seller like to calculate the cost of thedurian the customer have to pay. If the durian

cost RM2.50 per kilogram. Program a way forcalculating the total cost of durians for anamount in kilogram of durians sell.


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Defination & Analising ProblemDefination & Analising ProblemDefination & Analising ProblemDefination & Analising Problem

Understand the problem:Understand the problem:Understand the problem:Understand the problem: List the facts from the problem:

Price of a kilogram of durian is RM2.50 Additional information needed is the weight of

durian in Kilogram.

The total cost of durian Analising the problemAnalising the problemAnalising the problemAnalising the problem:

Define the input, output and the proces.

TotalWeight

(Kg)

CostCost = Total

weigrt xRM2.50


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Design the AlgorithmDesign the AlgorithmDesign the AlgorithmDesign the AlgorithmPseudo code:Pseudo code:Pseudo code:Pseudo code:Begin:Input:read the total weight

Proses:calculate cost :

cost = total weight x 2.50Output:display cost

End.


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Total Weight

Cost

Cost= Total Weight X 2.50

Begin

End

Design the Algorithm

Flow Chart


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#include

main ()

{

int weight, payment;

scanf ("%d", &weight);

payment = weight * 2;

printf ("The payment: RM%d.00", payment);

getch();

return 0;}


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Test using various data

bab 1 - introductory concepts

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