OVERVIEW OF COMPUTER AND PROGRAMMING

OVERVIEW OF COMPUTER AND PROGRAMMING

1.1 Computer Components and Operations1.2 Steps Involved in the Programming Process1.3 Interactive Input1.4 Data Hierarchy and File Input1.5 Flowchart Symbols and Pseudocode Statements1.6 Name Variables, Assign values to Variables1.7 Sentinel, or Dummy Value to End Program1.8 Manage Large Flowchart1.9 Data Types, the Evolution of Programming Techniques

COMPONENTS Hardware

equipment / device Software

instructions that tell the computer what to do

written by programmers. 2 types

System software Eg: OS, Windows, DOS, Unix

Application software Eg: Adobe, Ms Office, Games, etc

1.1 COMPUTER COMPONENTS AND

OPERATIONS

OPERATIONS1. Input

keyboard, mice, data2. Processing

CPU (Central Processing Unit)3. Output

printer, monitor, information 4. Storage

magnetic disks, tapes, compact discs, flash media

1.1 COMPUTER COMPONENTS AND OPERATIONS (CONT…)

PROCESS

INPUT

OUTPUT


Programming language Eg: Visual basic, C, C++, Java, COBOL

Machine language Binary form – 0,1

Compiler / interpreter The language translation software that convert a

programmer’s statement to binary form Storage

Internal storage – RAM (volatile)External storage – floppy disk, hard disk, flash

media (permanent) Language syntax

Rules governing its word usage and punctuation.


TRUE

FALSE

TRUE

TWO TRUTH AND A LIE1. Application software comprises the

programs that you use to manage your computer such as operating systems

2. Data includes all the text, numbers and other information that are processed by a computers

3. Programming languages have rules governing word usage and punctuation; these rules are called the language’s syntax.

1.2 STEPS INVOLVED IN THE PROGRAMMING

PROCESS Six Programming Steps

1. Understanding the problem2. Planning the logic3. Coding the program4. Using software to translate the

program into machine language5. Testing the program6. Putting the program into production

1. UNDERSTANDING THE PROBLEMUnderstand the whole problemProgrammer ask user, what they needDifficult aspects of programmingExample :

Sistem pendaftaran pelajarProgrammer ask staff management, what they want in the system

• NAME• NO MATRIK• NO KP• ADDRESS.• NO PHONE

1.2 STEPS INVOLVED IN THE PROGRAMMING PROCESS (CONT…)

2. PLANNING THE LOGICProgrammer plan the steps of the programPlanning tools

• Pseudocode• flowchart

Doesn’t worry about syntaxSequence of events (input / output)Desk checking

Program’s logic on paper before write the program.


3. CODING THE PROGRAM Convert the logic (pseudocode/flowchart)

into programming Use Programming language (C, C++, Java,

etc) Input operations Arithmetic processing Output operations Other standard functions

Using the corrects syntax CODING

Writing the statements in a programming language.


4. USING SOFTWARE TO TRANSLATE THE PROGRAM INTO MACHINE LANGUAGEComputer understand – machine

language(binary number – 0,1)Translator / Compiler / Interpreter

Change English-like high-level programming language in which programmer writes into the low-level machine language that the computer understands.

Syntax error Error in language and grammar


5. TESTING THE PROGRAMFree from logical error

Incorrect instruction are performed or Instructions are performed in the wrong

order

6. PUTTING THE PROGRAM INTO PRODUCTION Ready for the organization to use.



SPESIFIKASI MASALAH

/KEPERLUAN

ANALISA & MEMBENTUK ALGORITMA

MENULIS ATURCARA(PENGATUCARAAN)

PENGATURCARAMENGUJI &

MENYAHRALAT(TESTING &

DEBUGGING)

LARIAN ATURCARAYANG TELAH

DIBANGUNKAN


TRUE

TRUE

FALSE

TWO TRUTH AND A LIE1. Understanding the programming problem

may be one of the most difficult aspects of programming

2. The two most commonly used logic-planning tools are flowchart and pseudocode

3. Flowcharting a program is a very different process if you will be using an older programming language instead of a newer one.

Data values entered from a keyboard Prompt – message displayed on a

monitor, asking the user for a response

Command prompt – (computer’s OS using text)

GUI – graphical environment

1.3 INTERACTIVE INPUT

Command Line Environment

GUI Environment

1.3 INTERACTIVE INPUT (CONT…)

1.3 INTERACTIVE INPUT (CONT…)

TRUE

TRUE

FALSE

TWO TRUTH AND A LIE1. A prompt is a message that is displayed

on a monitor, asking the user for a response.

2. The command prompt allows users to interact with a program in a graphical nontext environment.

3. The logic for a command line interactive program and a GUI interactive program basically the same.

o Eg: list thousands of people (personnel, student)

o Field – single data item (eg: name, address, salary)

o Records – groups of fileds (eg: Student record – NoMatrik, Grade)

o Files – groups of records (eg: Students in your class)

o Database - groups of files (tables)o Queries – related data items.

1.4 DATA HIERARCHY AND FILE INPUT

1.4 DATA HIERARCHY AND FILE INPUT (CONT…)

Bil Nama k/p Tel Bil Nama K/P Tel

Nama Alamat Asrama

Nama

K/P PNG PNGK

K/P Gaji

Nama Bil Anak Alamat Tel

BIODATA PELAJAR BIODATA PENSYARAH

PENGINAPAN PELAJAR

RESULT PELAJAR

GAJI PENSYARAH

MAKLUMAT KELUARGA

Field

RecordFile

1.4 DATA HIERARCHY AND FILE INPUT (CONT…)

TRUE

TRUE

FALSE

TWO TRUTH AND A LIE1. In the data hierarchy, a field is a single

data item, such as lastname, streetaddress or salary.

2. In the data hierarchy, fields are grouped together to form a record; record are groups of fields that go together for some logical reason.

3. In the data hierarchy, related records are grouped together to form a field.

1. Nyatakan empat (4) operasi komputer2. Senaraikan enam (6) proses pengaturcaraan3. Berikan tiga (3) contoh bahasa pengaturcaraan4. Apakah tugas “Programmer”?5. Terangkan secara ringkas fasa ke-2 dalam proses

pengaturcaraan.6. Terangkan secara ringkas maksud ungkapan di bawah:

a) Promptb) Machine languagec) Command promptd) Logical errore) Syntaxf) Softwareg) Desk-checkingh) Compileri) coding

LATIHAN (1.1 – 1.4)

FLOWCHART Pictorial representation of the logical steps it

takes to solve a problem.PSEUDOCODE English-like representation of the same thing.

WRITING PSEUDOCODE

1.5 FLOWCHART SYMBOLS AND PSEUDOCODE

STATEMENTS

Pseudocode Not final product Flexible

Example Start/stop begin/end Input myNumber get myNumber

read myNumber set myAnswer = myNumber * 2 calculate myAnswer = myNumber times 2 compute myAnswer as myNumber doubled myAnswer = myNumber * 2

Output myAnswer display myAnswer write myAnswer print myAnswer

1.5 FLOWCHART SYMBOL AND PSEUDOCODE STATEMENTS (CONT…)

DRAWING FLOWCHARTS


• Parallelogram - input symbol

• Rectangle - processing symbol

• Parallelogram - output symbol

• Arrow / Flowlines- Connect the steps

• Terminal symbols- Start / Stop

Flowchart and pseudocode of program that doubles a number


After developed flowchart or pseudocode1. Buy a computer2. Buy a language compiler3. Learn a programming language4. Code the program5. Attempt to compile it6. Fix the syntax error7. Compile it again8. Test with several sets of data9. Put into production




VARIABLES / IDENTIFIERName memory location. Eg:

RULES FOR NAMING VARIABLES.1. Must be one word (no space)2. Cannot used any symbol (eg: > + ) & $ @

# . ? )3. Some appropriate meaning4. Cannot start with number

1.6 NAME VARIABLES, ASSIGN VALUES TO

VARIABLES

myNumber calculatedAnswer2 44 85 10

Suggested Variable Names for Pelajar’s

Comments

namaPelajar GoodnamaPljr Goodnpljr Legal – but crypticnamaPelajarKolejShahputra Legal – but awkwardnama pelajar Not legal – embedded spaceNama_pelajar Legalnamapelajar Legal – but hard to read without

camel casingnama+Pelajar Not legal – symbol ‘+’Nama2_pljr Legal2_namaPljr Not legal – start with number_2namaPljr Legal

1.6 NAME VARIABLES, ASSIGN VALUES TO VARIABLES(CONT…)

ASSIGNMENT STATEMENTS Eg: calculatedAnswer = inputNumber*2

luasSegiempat = panjang * lebarkuasa_3 = nom * nom * nompurata = (Uj1+Uj2+Uj3)/3punca = b*b – (4*a*c)

Assignment operator Equal signLeft side – name the location where the

result will be stored Rules of precedence

Eg d = a + b * cd = (a + b) * c



TRUE

TRUE

FALSE1. The equal assignment operator always

requires the name of a memory location on its right side.

2. Variable names are easier to remember than memory addresses.

3. A variable name is also called an identifier.

TRUE4. Variable names must be one word, without spaces

5. As a programmer, you choose specific memory addresses for your variables. FALSE

Bina pseudocode utk soalan 1 dan 2, Bina cartalir utk soalan 3 dan 4.

1. Mengira luas segitiga2. Mencari kuasa 4 bagi nombor yang

dimasukkan3. Mengira isipadu sfera

isipadu = 4/3 j34. Mengira gaji

Gaji = (jam * 5.00) + bonus + elaun

LATIHAN

Infinite loopRepeating flow of logic with no end

Making decisionTesting a valueUse decision symbol (diamond shape)

Dummy value / Sentinel valuePreselected value that stops the execution of a program

eofend-of-file

1.7 SENTINEL, OR DUMMY VALUE TO END

PROGRAM

1.7 SENTINEL, OR DUMMY VALUE TO END PROGRAM (CONT…)

Start

get No

No = 0?

Ans = No * 2

print Ans

Stop

Start

get No

eof?

Ans = No * 2

print Ans

Stop

Program with sentinel value of 0 Flowchart using eof

1.7 SENTINEL, OR DUMMY VALUE TO END PROGRAM (CONT…)

TRUE

TRUE

FALSE

TWO TRUTH AND A LIE1. A program that contains an infinite loop is

one that never ends.

2. A preselected value that stops the execution of a program is often called a dummy value or a sentinel value.

3. Many programming languages use the term fe (for “file end”) to talk about a marker that automatically acts as a sentinel.

on-page connector symbol Circle

off-page connector symbol Square with pointed bottom

1.8 MANAGE LARGE FLOWCHART

Flowchart using the connector

1.8 MANAGE LARGE FLOWCHART(CONT…)

start

Step 1

Step 1

Step 1

1

1

Step 1

Step 1

Step 1

p.2 A

1.8 MANAGE LARGE FLOWCHART(CONT…)

TRUE

TRUE

FALSE

TWO TRUTH AND A LIE1. You can use a connector when limited

page size forces you to continue a flowchart in an unconnected location or on another page.

2. By convention, programmers use a parallelogram as an on-page connector symbol.

3. By convention, programmers use a symbol that look like a square with a pointed bottom as an off-page connector symbol.

DATA TYPES Text

String constant / text constantString variable / text variable

NumericNumeric constantNumeric variable

• Integer• Floating-point (fractional)

1.9 DATA TYPES, THE EVOLUTION OF

PROGRAMMING TECHNIQUE

Constant – value doesn’t

change

Variable– value can change

1.9 DATA TYPES, THE EVOLUTION OF PROGRAMMING TECHNIQUES (CONT…)

Bil Nama NoKP PNG Jantina Kolej Gred Byrn1 Farah 11122233

33.45 P Sputra A 45.00

2 Mamat 666444777

2.99 L IKIP B 23.45

3 Isa 333555888

2.45 L PSDC C 56.50

4 Sofea 444999222

3.90 P Sputra A 44.40• Numeric Integer – Bil, NoKP• Numeric Floating point – PNG, Byrn• Text string – Nama, Kolej• Text char – Jantina, Gred

Example:

Variable

• Numeric Integer - Markah = 90• Numeric Floating point – PIE = 3.142• Text string – Nama = “Siti”• Text char – Gred = “E”

Constant

Example: LuasS4 = Panjang * Lebar

Numeric Integer – LuasS4, Panjang, Lebar

LuasS3 = 0.5 * Tapak * TinggiNumeric Integer – Tapak, TinggiNumeric floating point – LuasS3

Gaji = (jam * 5.50) + elaun + BonusNumeric floating point – Gaji, elaun, Bonus, jam

If Markah >= 80Gred = ‘A’Numeric Integer – MarkahText char – Gred


EVOLUTION OF PROGRAMMING TECHNIQUES Procedural programming

Focuses on the procedure (programmers create)

Input Proses Output Object-oriented programming

Focuses on objects or “thing”Describe features, attributes, behaviors

DDC1023 – focuses on procedural programming techniques.



TRUE

TRUE

FALSE

1. A Variable’s data type describes the kind of values the variable can hold and the types of operations that can be performed with it. 2. If name is a string variable, then the statement name=“Ed” is valid.

3. If salary is a numeric variable, then the statement salary=“12.50” is valid.

4. Procedural programmers focus on actions that are carried out by a program.

TRUE

5. Object-oriented programmers focus on a program’s objects and their attributes and behaviors.

TRUE

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OVERVIEW OF COMPUTER AND PROGRAMMING