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Transcript of chapter 2 C++
Starting Out with C++, 3rd Edition1
Chapter 02. Fundamental of C++
By Tariq Rashid Khan
Starting Out with C++, 3rd Edition2
Program 2-1
//A simple C++ program#include <iostream.h>
Main(){cout<< “Programming is great fun!”;
}
Program Output:Programming is great fun!
Starting Out with C++, 3rd Edition3
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
Starting Out with C++, 3rd Edition4
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
Starting Out with C++, 3rd Edition5
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
Starting Out with C++, 3rd Edition6
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
Starting Out with C++, 3rd Edition7
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();}
Starting Out with C++, 3rd Edition8
Program Output
Transistor and diodesElectronics Components Transistor TypesBJT,Mosfet,FETBe happy
Starting Out with C++, 3rd Edition9
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();}
Starting Out with C++, 3rd Edition10
Program Output
Transistor and diodesElectronics Components Transistor TypesBJT,Mosfet,FETBe happy
Starting Out with C++, 3rd Edition11
Program 2-5
#include<iostream.h>#include<iomanip.h>#include<conio.h>main(){clrscr();cout<<setw(15)<<"university"<<setw(15)<<"ranking";getch();}
Starting Out with C++, 3rd Edition12
Program Output
university ranking
Starting Out with C++, 3rd Edition13
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();}
Starting Out with C++, 3rd Edition14
Program Output
20 30 222 333 444 666
Starting Out with C++, 3rd Edition15
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
Starting Out with C++, 3rd Edition16
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.
Starting Out with C++, 3rd Edition17
Program 2-7
#include <iostream.h>#include<conio.h>main(){ int value; value = 555; cout<<"The value is "<< value <<endl; getch(); }
Starting Out with C++, 3rd Edition18
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.
Starting Out with C++, 3rd Edition19
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.
Starting Out with C++, 3rd Edition20
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();}
Starting Out with C++, 3rd Edition21
Program Output
99920145.5University
Starting Out with C++, 3rd Edition22
Program 2-9
#include <iostream.h>
void main (void){ int apples; apples = 25; cout<< “Today we sold “ << apples << “ bushels\n”; cout << “of apples.\n”;}
Starting Out with C++, 3rd Edition23
Program Output
Today we sold 25 bushels of apples.
Where are the constants in program 2-10?
Starting Out with C++, 3rd Edition24
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
Starting Out with C++, 3rd Edition25
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.
Starting Out with C++, 3rd Edition26
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
Starting Out with C++, 3rd Edition27
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();
}
Starting Out with C++, 3rd Edition28
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.
Starting Out with C++, 3rd Edition29
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";
}
Starting Out with C++, 3rd Edition30
Program Output
UET Abbottabad boys Hostel has 3 floorswith 100 rooms and 1 hall..
Starting Out with C++, 3rd Edition31
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
Starting Out with C++, 3rd Edition32
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
Starting Out with C++, 3rd Edition33
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;
}
Starting Out with C++, 3rd Edition34
Program Output
AB
Starting Out with C++, 3rd Edition35
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;
}
Starting Out with C++, 3rd Edition36
Program Output
AB
Starting Out with C++, 3rd Edition37
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';
}
Starting Out with C++, 3rd Edition38
2.9 The bool Data Type
• Boolean variables are set to either true or false
Starting Out with C++, 3rd Edition39
Program 2-16#include <iostream.h>
void main (void){ bool boolValue; boolValue = true; cout << boolValue << endl; boolValue = false; cout << boolValue << endl;}
Starting Out with C++, 3rd Edition40
Program Output
10Internally, true is represented as the number 1 and false is
represented by the number 0.
Starting Out with C++, 3rd Edition41
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.
Starting Out with C++, 3rd Edition42
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.
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// 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
Starting Out with C++, 3rd Edition44
Program output: depend upon numbers! Wait
Starting Out with C++, 3rd Edition45
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.
Starting Out with C++, 3rd Edition46
#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
Starting Out with C++, 3rd Edition47
Program Output
sum=18b=3
Starting Out with C++, 3rd Edition48
// 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
Starting Out with C++, 3rd Edition49
Program Output: depend upon numbers
Starting Out with C++, 3rd Edition50