DDC2133 c++ Topic1

8/13/2019 DDC2133 c++ Topic1

1/31

Liang, Introduction to C++ Programming, (c) 2007 Pearson Education, Inc. All rights reserved.013225445X 1

Chapter 1 Introduction to Computers,Programs, and C++

Lecturer: Mrs Rohani Hassan

UTM

8/13/2019 DDC2133 c++ Topic1

2/31


Objectives

To review computer basics, programs, and operating systems( 1.2-1.4).(Optional) To represent numbers in binary, decimal, andhexadecimal ( 1.5 Optional).To know the history of C++ (1.6).To write a simple C++ program (1.7).To understand the C++ program development cycle (1.8).To develop C++ using C++Builder (1.9).To develop C++ using command line tools on Windows (1.10).To develop C++ using command line tools on Unix (1.11).To develop C++ using Visual C++.Net (1.12).

8/13/2019 DDC2133 c++ Topic1

3/31


What is a Computer?

A computer consists of a CPU, memory, hard disk, floppy disk,monitor, printer, and communication devices.

CPU

e.g., Disk, CD,and Tape

InputDevices

e.g., Keyboard,Mouse

e.g., Monitor,Printer

CommunicationDevices

e.g., Modem,and NIC

StorageDevices Memory

OutputDevices

Bus

8/13/2019 DDC2133 c++ Topic1

4/31


CPUThe central processing unit (CPU) is the brain of a computer. Itretrieves instructions from memory and executes them. The CPUspeed is measured in megahertz (MHz), with 1 megahertz equaling 1million pulses per second. The speed of the CPU has been improvedcontinuously. If you buy a PC now, you can get an Intel Pentium 4

Processor at 3 gigahertz (1 gigahertz is 1000 megahertz).

CPU


InputDevices




e.g., Modem,and NIC


Output

Devices

Bus

8/13/2019 DDC2133 c++ Topic1

5/31


Memory Memory is to store data and program instructions for CPU toexecute. A memory unit is an ordered sequence of bytes, each holdseight bits. A program and its data must be brought to memory beforethey can be executed. A memory byte is never empty, but its initialcontent may be meaningless to your program. The current content of

a memory byte is lost whenever new information is placed in it.

CPU


Input

Devices



Communication

Devices e.g., Modem,

and NIC


Output

Devices

Bus

8/13/2019 DDC2133 c++ Topic1

6/31

8/13/2019 DDC2133 c++ Topic1

7/31


Storage DevicesMemory is volatile, because information is lost when the power isoff. Programs and data are permanently stored on storage devicesand are moved to memory when the computer actually uses them.There are three main types of storage devices:Disk drives (hard disksand floppy disks), CD drives (CD-R and CD-RW), and Tape drives.

CPU


InputDevices




e.g., Modem,and NIC


OutputDevices

Bus

8/13/2019 DDC2133 c++ Topic1

8/31


Output Devices: MonitorThe monitor displays information (text and graphics). The resolutionand dot pitch determine the quality of the display.

CPU


InputDevices




e.g., Modem,and NIC


OutputDevices

Bus

8/13/2019 DDC2133 c++ Topic1

9/31


Monitor Resolution and Dot PitchThe resolution specifies the number of pixels per squareinch. Pixels (short for picture elements) are tiny dots thatform an image on the screen. The resolution can be setmanually. The higher the resolution, the sharper and clearerthe image is. However, the image may be very small if you

set high resolution on a small screen monitor. PC monitorsare usually 15-inch, 17-inch, 19-inch, or 21-inch. For a 15-inch monitor, a comfortable resolution setting would be640 480 (307,200 pixels).

resolution

The dot pitch is the amount of space between pixels. Thesmaller the dot pitch, the better the display.

dot pitch

8/13/2019 DDC2133 c++ Topic1

10/31


Communication DevicesA regular modem uses a phone line and can transfer data in a speed up to

56,000 bps (bits per second). A DSL (digital subscriber line) also uses a phone line and can transfer data in a speed 20 times faster than a regularmodem. A cable modem uses the TV cable line maintained by the cablecompany. A cable modem is as fast as a DSL. Network interface card( NIC ) is a device to connect a computer to a local area network (LAN).

The LAN is commonly used in business, universities, and governmentorganizations. A typical type of NIC, called 10BaseT , can transfer data at10 mbps (million bits per second).

CPU


InputDevices




e.g., Modem,and NIC


OutputDevices

Bus

8/13/2019 DDC2133 c++ Topic1

11/31


Programs

Computer programs , known as software , are instructions tothe computer.

You tell a computer what to do through programs. Without programs, a computer is an empty machine. Computers donot understand human languages, so you need to usecomputer languages to communicate with them.

Programs are written using programming languages.

8/13/2019 DDC2133 c++ Topic1

12/31


Programming LanguagesMachine Language Assembly Language High-Level Language

Machine language is a set of primitive instructions built into every computer. The instructions are inthe form of binary code, so you have to enter binary

codes for various instructions. Program with nativemachine language is a tedious process. Moreoverthe programs are highly difficult to read andmodify. For example, to add two numbers, youmight write an instruction in binary like this:

1101101010011010

8/13/2019 DDC2133 c++ Topic1

13/31



Assembly languages were developed to make programmingeasy. Since the computer cannot understand assemblylanguage, however, a program called assembler is used toconvert assembly language programs into machine code.For example, to add two numbers, you might write aninstruction in assembly code like this:

ADDF3 R1, R2, R3

ADDF3 R1, R2, R3

Assembly Source File

Assembler 1101101010011010

Machine Code File

8/13/2019 DDC2133 c++ Topic1

14/31



The high-level languages are English-like and easy to learnand program. For example, the following is a high-levellanguage statement that computes the area of a circle with

radius 5:area = 5 * 5 * 3.1415;

8/13/2019 DDC2133 c++ Topic1

15/31


Popular High-Level LanguagesCOBOL (COmmon Business Oriented Language)FORTRAN (FORmula TRANslation)BASIC (Beginner All-purpose Symbolic Instructional Code)Pascal (named for Blaise Pascal)

Ada (named for Ada Lovelace)C (whose developer designed B first) Visual Basic (Basic-like visual language developed by Microsoft)Delphi (Pascal-like visual language developed by Borland)C++ (an object-oriented language, based on C)Java (a popular object-oriented language, similar to C++)C# (a Java-like developed my Microsoft)

8/13/2019 DDC2133 c++ Topic1

16/31


Compiling Source CodeA program written in a high-level language is called asource program . Since a computer cannot understand asource program. Program called a compiler is used totranslate the source program into a machine language

program called an object program . The object program isoften then linked with other supporting library code beforethe object can be executed on the machine.

CompilerSource File Object File Linker Excutable File

8/13/2019 DDC2133 c++ Topic1

17/31

8/13/2019 DDC2133 c++ Topic1

18/31


Number Systems NOTE: You can skip this section and use it as reference when you

have questions regarding binary and hexadecimal numbers.

0, 1

0, 1, 2, 3, 4, 5, 6, 7

0, 1, 2, 3, 4, 5, 6, 7, 8, 9

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F

binary

octal

decimal

hexdecimal

8/13/2019 DDC2133 c++ Topic1

19/31


Number SystemsComputers use binary numbers internally because storage deviceslike memory and disk are made to store 0s and 1s. A number or atext inside a computer is stored as a sequence of 0s and 1s. Each 0and 1 is called a bit , short for binary digi t . The binary numbersystem has two digits, 0 and 1.

Binary numbers are not intuitive, since we use decimal numbers inour daily life. When you write a number like 20 in a program, it isassumed to be a decimal number. Internally, computer software isused to convert decimal numbers into binary numbers, and viceversa.

8/13/2019 DDC2133 c++ Topic1

20/31


Number Systems, cont.The digits in the decimal number system are 0, 1, 2, 3, 4, 5, 6, 7, 8,

and 9. A decimal number is represented using a sequence of one ormore of these digits. The value that each digit in the sequencerepresents depends on its position. A position in a sequence has avalue that is an integral power of 10. For example, the digits 7, 4, 2,and 3 in decimal number 7423 represent 7000, 400, 20, and 3,respectively, as shown below:

The decimal number system has ten digits and the position values

are integral powers of 10. We say that 10 is the base or radix of thedecimal number system. Similarly, the base of the binary numbersystem is 2 since the binary number system has two digits and the

base of the hex number system is 16 since the hex number systemhas sixteen digits.

103

7 4 2 3

102 10 1 10 0

0123 103102104107

3204007000 7423

8/13/2019 DDC2133 c++ Topic1

21/31

8/13/2019 DDC2133 c++ Topic1

22/31

8/13/2019 DDC2133 c++ Topic1

23/31


Decimals => Binary To convert a decimal number d to a binary number is to find the

binary digits.. such that

These numbers can be found by successively dividing d by 2 until the quotient

is 0. The remainders are

For example, the decimal number 123 is 1111011 in binary. The conversion isconducted as follows:

01221 ,,,...,,, bbbbbb nnn

01221 222...222 01221 bbbbbbd nnn nnn

01221 ,,,...,,, bbbbbb nnn

1232

61

122

1

b 0

612

30

60 1

b 1

302

15

30

0

b 2

152

7

14 1

b 3

Remainder

Quotient

72

3

6

1

b 4

32

1

2 1

b 5

12

0

0

1

b 6

8/13/2019 DDC2133 c++ Topic1

24/31

8/13/2019 DDC2133 c++ Topic1

25/31

8/13/2019 DDC2133 c++ Topic1

26/31


Decimals => Hexadecimal

To convert a decimal number d to a hexadecimal number is to findthe hexadecimal digits hn, hn-1, hn-2, ... such that

01221 161616...161616 01221 hhhhhhd nnn nnn

These numbers can be found bysuccessively dividing d by 16 until thequotient is 0. The remainders are

For example, the decimal number 123 is7B in hexadecimal. The conversion isconducted as follows:

01221 ,,,...,,, hhhhhh nnn

nnn hhhhhh ,,,...,,, 12210

12316

7

112

11

h 0

716

0

0 7

h 1

Remainder

Quotient

8/13/2019 DDC2133 c++ Topic1

27/31


Hexadecimal Binary

0000 0 00001 1 10010 2 20011 3 30100 4 40101 5 50110 6 60111 7 71000 8 81001 9 91010 A 101011 B 111100 C 121101 D 131110 E 141111 F 15

Binary Hex DecimalTo convert a hexadecimal number to a binary

number, simply convert each digit in thehexadecimal number into a four-digit binarynumber.

To convert a binary number to a hexadecimal,

convert every four binary digits from right to leftin the binary number into a hexadecimal number.For example,

1 1 1 0 0 0 1 1 0 1

D83

8/13/2019 DDC2133 c++ Topic1

28/31

8/13/2019 DDC2133 c++ Topic1

29/31

8/13/2019 DDC2133 c++ Topic1

30/31

8/13/2019 DDC2133 c++ Topic1

31/31

Liang Introduction to C++ Programming (c) 2007 Pearson Education Inc All rights reserved

Creating,Compiling, and

RunningPrograms Source Code

Create/Modify Source Code

Compiler

Executable Code

Run Executable Codee.g., Welcome

Result

If compilation errors

If runtime errors or incorrect result

#include

int main(){

// Display Welcome to C++ to the consolestd::cout

DDC2133 c++ Topic1

Documents

Transcript of DDC2133 c++ Topic1