The document contains multiple Java programs demonstrating various concepts of object-oriented programming, including constructor overloading, single, multilevel, hierarchical, and hybrid inheritance. Each program defines classes and methods to illustrate how objects can inherit properties and behaviors from other classes, as well as perform operations based on user input. Outputs from the programs showcase the features and functionality implemented in each example.

1. //Program for Constructor Overloading
import java.io.*;
import java.util.Scanner;
class Emp
{
String ename;
int eid;
float salary;
Emp()
{
eid=100;
ename="Ram";
salary=30000;
}
Emp(String ename,int id,float sal)
{
this.ename=ename;
eid=id;
salary=sal;
}
void display()
{
System.out.println("Ename=" +ename);
System.out.println("ID=" +eid);
System.out.println("Salary=" +salary);
}
public static void main(String args[])
{
Emp e=new Emp();
e.display();
Emp e1=new Emp("Rahul",101,40000);
e1.display();
}
}

2. //Program for Single Inheritance
import java.io.*;
class Emp // base class
{
String ename;
int eid;
protected float salary;
void get(String ename, int id, float sal)
{
this.ename=ename;
eid=id;
salary=sal;
} }
class Pay extends Emp // derived class
{
void display()
{
System.out.println("Ename=" +ename);
System.out.println("ID=" +eid);
System.out.println("Salary=" +salary);
}}
public class main
{
public static void main(String args[])
{
Pay ob = new Pay();
ob.get(“Sai”,112,60000);
ob.display();
}}
Output:
Ename=Sai
ID=112
Salary=60000.0

3. //Program for multilevel Inheritance
import java.io.*;
class Emp // base class
{
String ename;
int eid;
protected float salary;
void get(String ename, int id, float sal)
{
this.ename=ename;
eid=id;
salary=sal;
}
}
class Pay extends Emp // derived class
{
protected double hra,da,pf,gpay,netpay;
void paycal()
{
hra=salary*0.10;
da= salary*0.15;
pf= salary*0.12;
}
}
class Grosspay extends Pay
{
void payroll()
{
gpay=salary+hra+da+pf;
netpay=gpay-pf;
}
void display()
{
System.out.println("Ename=" +ename);
System.out.println("ID=" +eid);
System.out.println("Salary=" +salary);
System.out.println("Grosspay=" +gpay);
System.out.println("Netpay=" +netpay);
}
}
public class main
{
public static void main(String args[])
{
Grosspay ob = new Grosspay();
ob.get(“Sai”,112,60000);
ob.paycal();
ob.payroll();
ob.display();
}

4. }
Output:
Ename=Sai
ID=112
Salary=60000.0
Grosspay=82200.0
Netpay=75000.0

5. //Hierarchical Inheritance
import java.io.*;
import java.util.*;
class College // base class
{
String sname;
int sid;
protected float fees;
void show()
{
Scanner s= new Scanner(System.in);
sname=s.next();
sid=s.nextInt();
System.out.println("name=" +sname);
System.out.println("ID=" +sid);
} }
class Engg extends College // derived class
{
String course;
void Enggcourse(float fees)
{
System.out.println("Enter Engg Course");
Scanner s= new Scanner(System.in);
course=s.next();
this.fees=fees;
System.out.println("Engg Course=" +course);
System.out.println("Fees Details=" +fees);
}}
class Arts extends College // derived class
{
String course1;
void artscourse(float fees)
{
System.out.println("Enter Arts Course");
Scanner s= new Scanner(System.in);
course1=s.next();
this.fees=fees;
System.out.println("Engg Course=" +course1);
System.out.println("Fees Details=" +fees);
}}
public class main
{
public static void main(String args[])
{
Engg e = new Engg();
e.show();
e.Enggcourse(100000);
Arts a = new Arts();
a.artscourse(80000);
}}

6. Output:
Ram
112
name=Ram
ID=112
Enter Engg Course
AI
Engg Course=AI
Fees Details=100000.0
Enter Arts Course
B.Com
Engg Course=B.Com
Fees Details=80000.0

7. //Hybrid Inheritance
import java.io.*;
import java.util.*;
class Student // base class
{
String sname;
int sid;
protected float m1,m2,m3;
void show()
{
Scanner s= new Scanner(System.in);
sname=s.next();
sid=s.nextInt();
System.out.println("name=" +sname);
System.out.println("ID=" +sid);
} }
class Marks extends Student // derived class
{
protected float sum,avg;
void cal()
{
System.out.println("Enter marks");
Scanner s= new Scanner(System.in);
m1=s.nextFloat();
m2= s.nextFloat();
m3= s.nextFloat();
sum=m1+m2+m3;
avg=sum/3;
System.out.println("Total =" +sum);
System.out.println("Average=" +avg);
}}
class Grade extends Marks // derived class
{
void result()
{
if(m1>=40 && m2>=40 && m3>=40)
System.out.println ("Pass");
else
System.out.println("Fail");
}}
class Placement extends Marks
{
void check()
{
if(m1>=70 && m2>=70 && m3>=70)
System.out.println("Eligible");
else
System.out.println("not Eligible");
}}

8. public class main
{
public static void main(String args[])
{
Grade g = new Grade();
g.show();
g.cal();
g.result();
Placement p=new Placement();
p.check();
}}
output :
sai
112
name=sai
ID=112
Enter marks
90
89
90
Total =269.0
Average=89.666664
Pass
Eligible