PROGRAMMING FOR ENGINEERS

By: MUBAREK KURT

INTRODUCTION TO COMPUTER AND PROGRAMMING

Chapter 1:

WHAT IS PROGRAMMING?

• A set of instruction given to computer forexecuting certain tasks

• Using computer language such as C++, Fortran,Cobol etc

• Language comes with rules• A commercial program is called

a software

BASIC STRUCTURE OF A PROGRAM

• 3 main stages: input of data, Processing of dataand producing results.

Data input

Dataprocessing

Producing result

Arithmatic Solution

Logical Operation

WHY PROGRAMMING IS IMPORTANT?

• We give difficult or easy tasks to computer to beexecuted.

• Problem solving in shorter time.• Software may not be available.• It’s money saving if you developed your

ownsoftware.

• To increase your copetency as an engineer.

WHY C++?

• Old language such as C do have its specialty but alsocontain weaknesses.

• Its specialty is as the pioneer language, many softwares are written using this language.

• Its weakness is it uses structural programming.

• C++ is an object oriented programming (OOP).

• Thus C++ has been the main computer language in the world.

COMPUTER COMPONENTS

• HARDWARE• SOFTWARE

COMPUTER LANGUAGES

1. Machine language

2.Assembly language

3. High level language

MACHINE LANGUAGE• Machine language is a combination

of binarydigit 1 and 0.

• Every number, letter and symbols can be translated to binary code.

• In computer programming, number, letterand symbols is called character.

• Main standard of conversion is the American Standard Code for Information Interchange (ASCII).

• In ASCII, there are 128 character, numbeed between 0 to 127 and this number is converted to binary number.

MACHINE LANGUAGEPositions Character Binary number in

ASCIIBinary number in Machine language

0 Null 0000000 00000000

1 SOTT 0000001 00000001

65 A 1000001 01000001

136 { 1111011 01111011

127 DEL 1111111 01111111

ASSEMBLY LANGUAGE

• Assembly language is also called low level language

• Contain pneumonic codes that have special meaning . For example, addition of 2 numbers to become the third number isADD N1, N2, N3

• The meaning of codes is machine dependent.

HIGHER LEVEL LANGUAGE

• Machine language that hss been standardly coded

• The language is like spoken language such as in english, japan and france.

• There are more than 100 higher level language. Eg:1.FORTRAN - FORmula TRANslation2. C3. C++ - Object oriented programming4.BASIC - Beginning All-purpose Symbolic

Instruction Code5. COBOL - Common Business Oriented

Language6.Java- Internet based language

developed by SunMicrosystem7. C#. Similar to Java, developed by

Microsoft Inc.

HIGHER LEVEL LANGUAGE

• Command to computer is easily given.

• For example, in C++, to add 2 numbers and keeping the answer,hasilTambah = no1 + no2;

• However computer will not understand this language. It needs a compiler to translate the language to machine language.

APPLICATION PROCESS IN C++

Source codes

Preprocessor

Modified source-

code

CompilerNo

error

Object codes

Linker

Executable codes

Library

DEVELOPING A PROGRAM

Analyzing the problem

Program Design using

Algorithm

Conversion to Program

Flow-chart Pseudo-code

ANALYZING THE PROBLEM

• At this stage, think about the required:1. Input2. Output3. Process

• Example: To develop a program to calculate a circumference of a circle, give the radius

• Problem analyzing stage:1. Input: Media – Keyboard

Data – a radius2. Output: Media – Screen

Data – Circumference3. Process: Circ = 2 x PAI x Radius

ALGORITHM• Algorithm is a step by step

procedure ofsolving a problem.– In the design stage.– No algorithm No program

Nosolution.

– Independent of computer language (use your own language)

ALGORITHM• What is needed in an

algorithm– input– output– Correct sequence: first

comes first– Simple/easy/non-confusing– In general form-understood

by any readers– Accurate in solving problem– Finite – has an end– Efficient

• Types: Pseudocodes, flow-chart etc

ALGORITHM• 3 forms of algorithm:

1. Sequential2. Control: decision

making3. Control : repeated

solution

ALGORITHM1. Sequential

algorithmStart

Step 1:

Step nEnd

2. Controlled algorithm: making decision

if conditionthen

true partelse

false partendif

ALGORITHM

•3. Controlled algotithm: Repeated solution

• While condition do• Repeated part

• or• Repeat n times

• Repeated part

ALGORITHM-PSEUDOCODES

• Sequential steps written in own language

• Each line is numbered.• Each line represent 1 step,

to beexecuted only one time.

• It can be:– In own language form

totally– In a mixed of own language

and programming language

ALGORITHM-PSEUDOCODES

• Example: Sequential algorithm• Pseudocode in own language

1. Start2. Read (input) the radius3. Circumference=2xxradius4. Write the circumference5. End

• Notice: The pseudocodes is numberedand in sequence.

ALGORITHM-PSEUDOCODES

• Pseudocode in mixed language1. Start2. cin the radius3. Circumference=2xxradius4. cout the circumference5. End

DECISION MAKINGALGORITHM

• Pseudocodes : making decision1. Start2. Read (input) the radius3. if radius < 0 then

3a. Write circumference cannot be calculated 3b. Stop

4. Else4a. Circumference=2xPAIxradius 4b. Write circumference

5. Endif6. End

DECISION MAKINGALGORITHM

• Pseudocodes : repeated solution-torepeat radius input

1. Start2. Read (input) the radius3. Circumference=2xPAIxradius4. Read yes or no to repeat5. While yes to repeat

do 5a. Go to 25. End

FLOW-CHART• Flow-chart contains boxes/symbols

that represent required operations and arrows to show the sequence.

• Symbols:– terminal (start, end)– process (assign value,

arithmatic operation, etc)– Input/ output

FLOW-CHART

– Document printing

– Decision making

– Loop (FOR)

– To continue on the same page

– To continue on different page

– Subrutine/ function

FLOW-CHARTSequential flow-chart Start

Read radius

Calculate Circumference=2xpaixradius

Write circumference

End

FLOW-CHART

Decision making flow- chart

CalculateCircumference=2xpaixradius

false

Start

Read radius

End

true Radius<0

Write circumference

Flow-chart for repeated solution

Start

Calculate Circumference=2xpaixradius

Write circumference

Continue?

noEND

yes

Read radius

Read intention to repeat

QUIZ

The second step before developing a program is

.

ASSIGNMENT 1

What is a flow-chart?