chapter 2 c++

Starting Out with C++, 3rd Edition1

Chapter 02. Fundamental of C++

By Tariq Rashid Khan


Program 2-1

//A simple C++ program#include <iostream.h>

Main(){cout<< “Programming is great fun!”;

}

Program Output:Programming is great fun!


Table 2-1

Character Name Description // double slash Marks the beginning of a comment. # Pound sign Marks the beginning of a preprocessor

directive < > Opening and

closing brackets

Encloses a filename when used with the #include directive

( ) Opening and closing parenthesis

Used in naming a function, as in int main ()

{ } Opening and closing braces

Encloses a group of statements, such as the contents of a function.

" " Opening and closing quotation marks

Encloses a string of characters, such as a message that is to be printed on the screen

; Semicolon Marks the end of a complete programming statement


2.2 The cout Object

• Use the cout object to display information on the computer’s screen. The cout object is referred to as the standard

output object. Its job is to output information using the

standard output device


Program 2-2// An unruly printing program#include <iostream.h>

main(){

cout << “Transistor and diodes";cout << “Electronics Components";cout << “Transistor Types";cout << “BJT,Mosfet,FET";cout << “be happy";

}

Program OutputTransistor and diodes……………………be happy


New lines(Manipulator and escape of sequence)

• cout does not produce a newline at the end of a statement

• To produce a newline, use either the stream manipulator endl

• or the escape sequence \n• Setw(n)• Tokens


Program 2-3

// A well-adjusted printing program#include<iostream.h>#include<conio.h>

main(){

cout<<"Transistor and diodes"<<endl;cout<<"Electronics Components"<<endl;cout<<" Transistor Types"<<endl;cout<<"BJT,Mosfet,FET"<<endl;cout<<"Be happy"<<endl;

getch();}


Program Output

Transistor and diodesElectronics Components Transistor TypesBJT,Mosfet,FETBe happy


Program 2-4// A well-adjusted printing program#include<iostream.h>#include<conio.h>

main(){

cout<<"Transistor and diodes\n";cout<<"Electronics Components\n";cout<<" Transistor Types\n";cout<<"BJT,Mosfet,FET\n";cout<<"Be happy\n";

getch();}


Program Output

Transistor and diodesElectronics Components Transistor TypesBJT,Mosfet,FETBe happy


Program 2-5

#include<iostream.h>#include<iomanip.h>#include<conio.h>main(){clrscr();cout<<setw(15)<<"university"<<setw(15)<<"ranking";getch();}


Program Output

university ranking


Program 2-6

#include<iostream.h>#include<iomanip.h>#include<conio.h>main(){clrscr();cout<<setw(8)<<"20"<<setw(8)<<30<<endl;cout<<setw(8)<<"222"<<setw(8)<<333<<endl;cout<<setw(8)<<"444"<<setw(8)<<666<<endl;getch();}


Program Output

20 30 222 333 444 666


2.3 The #include Directive

• The #include directive causes the contents of another file to be inserted into the program

• Preprocessor directives are not C++ statements and do not require semicolons at the end


2.4 Variables and Constants

• Variables represent storage locations in the computer’s memory. Constants are data items whose values do not change while the program is running.

• Every variable must have a declaration.


Program 2-7

#include <iostream.h>#include<conio.h>main(){ int value; value = 555; cout<<"The value is "<< value <<endl; getch(); }


Assignment statements:

Value = 555; //This line is an assignment statement.

• The assignment statement explain the expression on the right of the equal sign then stores it into the variable named on the left of the equal sign

• The data type of the variable was in integer, so the data type of the expression on the right should explain to an integer as well.


2.5 Constants and Variables

• A variable is called a “variable” because its value may be changed. A constant, on the other hand, is a data item whose value does not change during the program’s execution.


Program 2-8#include <iostream.h>#include<conio.h>main(){ int x= 999,y= 2014; float z = 5.5; char name[15]= "University"; cout<<x<<endl; cout<<y<<endl; cout<<z<<endl; cout<<name<<endl; getch();}


Program Output

99920145.5University


Program 2-9

#include <iostream.h>

void main (void){ int apples; apples = 25; cout<< “Today we sold “ << apples << “ bushels\n”; cout << “of apples.\n”;}


Program Output

Today we sold 25 bushels of apples.

Where are the constants in program 2-10?


Constants from Program 2-10

Constant Type of Constant 25 Integer constant "Today we sold " String constant " bushels\n" String constant "of apples.\n" String constant


2.6 Integer Data Types

• There are many different types of data. Variables are classified according to their data type, which determines the kind of information that may be stored in them. Integer variables only hold whole numbers.


Table 2-2

Table 2-5 Integer Data Types, Sizes and RangesData Type Size Rangeshort 2 Bytes -32,768 to +32.767unsigned short 2 Bytes 0 to +65,535int 4 Bytes -2,147,4833,648 to +2,147,4833,647unsigned int 4 Bytes 0 to 4,294,967,295long 4 Bytes -2,147,4833,648 to +2,147,4833,647unsigned long 4 Bytes 0 to 4,294,967,295


Program 2-11// This program has variables of several of the integer types.#include <iostream.h>#include<conio.h>

main(){

int checking;unsigned int miles;int years;

checking = -20;miles = 500;years = 5;cout << "We have made a long journey of " << miles;cout << " miles.\n";cout << "Our checking account balance is " << checking;cout << "\nExactly " << years << " years ago I was ";cout << "stood on this computer lab as a student.\n";

getch();

}


Program Output

We have made a long journey of 500 miles.Our checking account balance is -20Exactly 5 years ago I was stood on this computer lab as a student.


Program 2-12// This program shows three variables declared on the same// line.#include <iostream.h>#include<conio.h>main(){

int floors,rooms,hall;

floors = 3;rooms = 100;hall = 1;cout << “UET Abbottabad boys Hostel has " << floors << " floors\n";cout << "with " << rooms << " rooms and " << hall;cout << " hall.\n";

}


Program Output

UET Abbottabad boys Hostel has 3 floorswith 100 rooms and 1 hall..


2.7 Hexadecimal and Octal Constants

• Hexadecimal numbers are preceded by 0x Hexadecimal F4 would be expressed in C++ as

0xF4• Octal numbers are preceded by a 0

Octal 31 would be written as 031


2.8 The char Data Type

• Usually 1 byte long• Internally stored as an integer• ASCII character set shows integer

representation for each character• ‘A’ == 65, ‘B’ == 66, ‘C’ == 67, etc.• Single quotes denote a character, double

quotes denote a string


Program 2-13

// This program demonstrates the close relationship between// characters and integers.#include <iostream.h>

main(){

char letter;

letter = 65;cout << letter << endl;letter = 66;cout << letter << endl;

}


Program Output

AB


Program 2-14

// This program uses character constants#include <iostream.h>

void main(void){

char letter;

letter = 'A';cout << letter << endl;letter = 'B';cout << letter << endl;

}


Program Output

AB


Program 2-15// This program uses character constants#include <iostream.h>

void main(void){

char letter;

letter = 'A';cout << letter << '\n';letter = 'B';cout << letter << '\n';

}


2.9 The bool Data Type

• Boolean variables are set to either true or false


Program 2-16#include <iostream.h>

void main (void){ bool boolValue; boolValue = true; cout << boolValue << endl; boolValue = false; cout << boolValue << endl;}


Program Output

10Internally, true is represented as the number 1 and false is

represented by the number 0.


Program 2-17

#include <iostream.h>

void main (void){

int month = 2, days = 28;cout << “Month “ << month << “ has “ << days << “ days.\n”;

}

Program output:Month 2 has 28 days.


The Cin Object input Stream• Used as input statement to get input from

the keyboard during execution of the program.

• >> extration operator or to get from operator.


// This program demonstrates the summing and multiplication between two numbers#include <iostream.h>#include<conio.h>

void main (){ int a1,a2,y,z; clrscr(); cout<<"Enter first number"; cin>>a1;cout<<"Enter second number";cin>>a2;y=a1+a2;z=a1*a2;cout<<"sum of numbers="<<y<<endl;cout<<"product of numbers="<<z<<endl;getch();}

Program 2-18


Program output: depend upon numbers! Wait


Increment and decrement Operators

Like C C++ provides increment(++) and decrement(--) operators

++a denotes pre increment operator.a++ denotes post increment operator.--b denotes pre decrement operator.b-- denotes pre decrement operator.


#include <iostream.h>#include<conio.h>

void main (){ clrscr(); int a1,a2,b,sum; a1=5; a2=10; b=2; sum=a1+a2+(++b); cout<<"sum="<<sum; cout<<"b="<<b;getch();}

Program 2-19


Program Output

sum=18b=3


// This program demonstrates the power of a number#include<math.h>#include<conio.h>#include<iostream.h>void main(){clrscr();long int x,n;long int y;cout<<"value of x : ";cin>>x;cout<<"value of n : ";cin>>n;y=pow(x,n);cout<<"answer is : "<<y;getch();}

Program 2-20


Program Output: depend upon numbers

chapter 2 c++

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