constructor in inheritance

constructor call in derived class:

#include<iostream>
#include<conio.h>
using namespace std;
class base
{
    public:

    base()   //1st cal  instructor
    {
        cout<<"   base constructor calling"<<endl;

    }


};

class derive:public base
{
    public:
    derive() :base() //2nd call
    {
        cout<<"   derive constructor calling"<<endl;
    }

};

int main()
{

     derive obj;

     getch();
     return(0);

}


parametrized constructor call in inheritance:


#include<iostream>
#include<conio.h>
using namespace std;
class alpha
{

    int x;
public:
    alpha(int i)
    {

        x=i;
        cout<<"alpha intialized"<<endl;
        cout<<"x:  "<<x<<'\n';

    }
};

class beta
{
    int y;
public:

    beta(int j)
    {

         y=j;
        cout<<"beta is  intialized"<<endl;
        cout<<"y:  "<<y<<'\n';

    }
};

class gamma:public beta,public alpha
{

    int m,n;
public:
    gamma(int a,int b) : alpha(a),beta(b)
    {
        m=a;
        n=b;
        cout<<"m:  "<<m<<endl;
        cout<<"n:  "<<n<<endl;

    }


};
int main()
{
    gamma obj(5,10);
    cout<<"  "<<endl;
    getch();

    return(0);



}

Types of inheritance practical

practical 5:Inheritance

MULTILEVEL INHERITANCE:

 

#include<iostream>

#include<conio.h>

using namespace std;

class rectangle

{

protected:

    float length;

    float width;

public:

    void setlength()

    {

        cout<<"your length:  "<<endl;

        cin>>length;

        cout<<"your width:   "<<endl;

        cin>> width;

    }

};

class area : public rectangle

{

 public:

    float calc()

    {

        return(length*width);

    }

};

class peri: public area

{

    public:

    float calc1()

    {

        return (2*(length*width));

    }

};

int main()

{

    peri a;

    cout<<"enter the data for first rectangle to find the area:  "<<endl;

    a.setlength();

    cout<<"area is :   "<< a.calc() <<"sq/m"<<endl;

    cout<<"enter the data for  rectangle to find the perimeter:  "<<endl;

    a.setlength();

    cout<<"perimeter is:   "<< a.calc1() << "m" <<endl;

    getch();

    return(0);

}

MULTIPLE INHERITANCE :

#include<iostream>
#include<conio.h>
using namespace std;
class student
{

    protected:
    int no,m1,m2;
    public:
        student()
        {
            cout<<"enter the roll no. "<<endl;
            cin>>no;
            cout<<"enter the marks of two subject  "<<endl;
            cin>>m1>>m2;
        }

};


class sports
{
    protected:
    int spo;
    public:
        sports()
        {


           cout<<"enter the sports marks:  "<<endl;
           cin>>spo;
        }

};


class statement : public student ,public sports
{
    float total,avg;


    public:
    void display()
    {
        total=(m1+m2+spo);
        avg=total/3;
        cout<<"total marks is :  "<<total<<endl;
        cout<<"average is :       "<<avg<<endl;

    }



};


int main()
{
    statement obj;
    obj.display();

    getch();
    return(0);


}

Hierarchical inheritance:

#include<iostream>
#include<conio.h>
using namespace std;
class A          //base class
{
protected:
    int a;
public:
    void getnumber()
    {
        cout<<"enter the number  :...."<<endl;
        cin>>a;

    }
};

class B:public A
{
   public:
        int squr()
       {
           cout<<"square is  :  "<<(a*a)<<endl;
       }


};

class C :public A
{

    public:



        void qube()

    {



        cout<<"qube  is :  "<<(a*a*a)<<endl;;


    }

};


int main()
{
    B b1;
    b1.getnumber();
    b1.squr();
    C  c1 ;
    c1.getnumber();
    c1.qube();

    getch();
    return(0);

}

Hybrid inheritance:

#include<iostream>
#include<conio.h>
using namespace std;


class arithmetic
{
protected:
int num1, num2;
public:
void getdata()
{
cout<<"For Addition:";
cout<<"\nEnter the first number: ";
cin>>num1;
cout<<"\nEnter the second number: ";
cin>>num2;
}
};


class plusl:public arithmetic
{
protected:
int sum;
public:
void add()
{
sum=num1+num2;
}
};


class minusl
{
protected:
int n1,n2,diff;
public:
void sub()
{
cout<<"\nFor Subtraction:";
cout<<"\nEnter the first number: ";
cin>>n1;
cout<<"\nEnter the second number: ";
cin>>n2;
diff=n1-n2;
}
};


class result:public plusl, public minusl
{
public:
void display()
{
cout<<"\nSum of "<<num1<<" and "<<num2<<"= "<<sum;
cout<<"\nDifference of "<<n1<<" and "<<n2<<"= "<<diff;
}
};


int  main()
{
result z;
z.getdata();
z.add();
z.sub();
z.display();
getch();
return(0);
}

 

basic program on constructor and destructor

Example on constructor and destructor :

#include<iostream>
#include<conio.h>
using namespace std;
  static int countl;
 class test
 {

 public:
    test()
    {
        countl++;
         cout<<"\t\t  constructor msg:object"                <<countl<<"created....."<<endl;
    }


    ~test()
    {

        cout<<"\t\t  destructor msg:object  "   <<countl<<"destroy....."<<endl;
          countl--;
    }
 };


 int main()
 {

     cout<<"inside block...."<<endl<<endl;
     cout<<"creat object....."<<endl;

    {


         test t1;


      {
         cout<<"inside main block.."<<endl;
          cout<<"creat another two  object....."<<endl;
          test t2,t3;
          cout<<"leave the block....."<<endl;

        }

}

        cout<<"back to main block....."<<endl;
     getch();
     return(0);



 }