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C++ class program to illestrate File operations

Ranjith — Sat, 13 Mar 2010 18:08:00 +0000

AIM
Write a program to illustrate the write() member function which are usually used for transfer of data blocks to the file.

ALGORITHM

1. Start the process
2. Invoke the class
a. Create two inline member functions .ie, getdata() and dispdata()
i. getdata() for input
ii. dispdata() for display
3. Open the file in fstream mode
4. Write the data in to the file
5. Slose the file
6. Stop the process

PROGRAM

#include
#include
#include
class student
{
private:
int rno;
char name[10];
float fees;
public:
void getdata()
{
cout<<"roll number";
cin>>rno;
cout<<endl;
cout<<"enter name:";
cin>>name;
cout<<endl<<"enter fees:";
cin>>fees;
}
void dispdata()
{
cout<<"Roll number"<<rno<<endl;
cout<<"Name"<<name<<endl;
cout<<"Fees"<<fees;
}
};
 
void main()
{
student s1;
clrscr();
ofstream stdfile("c:\\std.txt");
//fstream stdfile;
//stdfile.open("c:\\std.txt",ios::out|ios::in);  //open file for output
char wish;
//writing to the file
do
{
s1.getdata();
stdfile.write((char*)&s1,sizeof(student));
cout<<"continue ? y/n";
cin>>wish;
}
while(wish=='y'||wish=='Y');
stdfile.close();   //close the file
 
getch();
}

OUTPUT

Roll number 121
Enter name Jacob
Enter fees 10000

c++ Program to illustrate the use of difference operators using friend function

Ranjith — Sat, 13 Mar 2010 04:29:18 +0000

AIM:
A program to illustrate the use of difference operators to access the class member using friend function

ALGORITHM:

1) Start the process
2) Invoke the classes
3) Call the set_xy() first
a) Assign the value of x and y
b) Print the value of x and y
4) Call the sum() for second(friend)
a) Again assign the temp value of x and y
5) Print the value of x and y
6) Stop the process

PROGRAM

#include
class M
{
int x;
int y;
public:
void set_xy(int a,int b)
{
x=a;
y=b;
}
friend int sum(M m);
};
int sum(M m)
{
int M ::* px=&M :: x;
int M ::* py=&M :: y;
M *pm=&m;
int s=m.*px + pm->*py;
return s;
}
main()
{
M n;
void (M :: *pf)(int,int)=&M :: set_xy;
(n.*pf)(10,20);
cout<<"Sum="<<sum(n)<<"\n";
M *op=&n;
(op->*pf)(30,40);
cout<<"Sum="<<sum(n)<<"\n";
return(0);
}

Output:

Sum=30
Sum=70

C++ program for implementation of class

Ranjith — Fri, 12 Mar 2010 09:45:07 +0000

AIM:
A program to solve a quadratic equation, using OOP techniques.

ALGORITHM:

1) Start the process
2) Invoke the classes
3) Get the input for a,b,c;
4) Call the function getinfo() and display()
5) Check if a=0
a) True : compute c/b;
i) Print the value of a/c;
b) False: compute b*b-4*a*c;
i) If ( b*b-4*a*c)=0
ii) Call img();
iii) Otherwise : call real(a,b,c);
6) Stop the process

PROGRAM:

	#include
	#include
		class equation
		{
			private:float a,b,c;
			public: void getinfo(float  a, float b,float c );
				void display( );
				void equal(float  a, float b);
				void imag( );
				void real(float a,float b,float c);
		};
		void  equation :: getinfo(float aa,float bb,float cc)
		{
	                a=aa;
			b=bb;
		        c=cc;
		}
		void equation::display( )
		{
			cout<<endl;
			cout<<”a=”<<a<<’\t’;
			cout<<”b=”<<b<<’\t’;
			cout<<”c=”<<c<<endl;
		}		
 
void equation ::equal (float a,float b)
		{
			float x;
			x = -b/(2*a);
			cout<<”Roots are equal “<<x<<endl;
		}
		void equation :: imag( )
		{
			cout<<”Roots are imaginary”;
		}
		void equation :: real(float a,float b,float det)
		{
			float x1,x2,temp;
			temp = sqrt(det);
			x1= (-b + temp)/(2*a);
			x2 = (-b –temp)/(2*a);
			cout<<”Roots are real”;
			cout<<”x1= “<<x1<<endl;
			cout<<”x2 =”<<x2<<endl;
		}
		void main( )
		{
			class equation e;
			float aa,bb,cc;
			clrscr( );
			cout<<”Enter the three numbers”;
			cin>>aa>>bb>>cc;
			e.getinfo(aa,bb,cc);
			e.display( );
			if(aa = =0)
			{
				float temp;
				temp = cc/bb;
				cout<<” Linear Roots”<<temp<<endl;
			}
			else
			{
				float det;
				det = (bb*bb – 4*aa*cc);
				if(det = =0)
				e.equal(aa,bb);
				else if (det<0 )
				          e.imag( );
				else 
				          e.real(aa,bb,cc );
			}
			getch( );
		}

OUTPUT:
Enter the three numbers 2 4 1
Roots are imaginary
X1= – 0.292893
X2= – 1.707107