Java.docx

**Name: Pranjal A Ojha** **Class: SYCS** **Roll No: 5255** **Practical 1** **Aim: Write a program to create a class and object in Java.** - **Class in Java:** A class in Java is a set of objects which shares common characteristics/ behaviour and common properties/ attributes. It is a user-de...

**Name: Pranjal A Ojha** **Class: SYCS** **Roll No: 5255** **Practical 1** **Aim: Write a program to create a class and object in Java.** - **Class in Java:** A class in Java is a set of objects which shares common characteristics/ behaviour and common properties/ attributes. It is a user-defined blueprint or prototype from which objects are created. For example, Student is a class while a particular student named Ravi is an object. - **Object in Java:** An object in Java is a basic unit of Object-Oriented Programming and represents real-life entities. Objects are the instances of a class that are created to use the attributes and methods of a class. A typical Java program creates many objects, which as you know, interact by invoking methods. 1. Create a class with the functions getdata to take the data from the user to calculate the simple interest and a function to display the output. **Source Code:** import java.util.Scanner; class SimpleIntr {     Scanner sc;     int p,n;     float r,si;     void getData()     {         sc=new Scanner(System.in);         System.out.println(\"Enter the principal amount: \");         p=sc.nextInt();         System.out.println(\"Enter Number of years: \");         n=sc.nextInt();         System.out.println(\"Enter the rate of interest: \");         r=sc.nextFloat();     }     void display()     {         si=(p\*r\*n)/100;         System.out.println(\"The Simple Interest is: \"+si);     }     public static void main(String arg\[\])     {         SimpleIntr s = new SimpleIntr();         s.getData();         s.display();     } } **Output:** **Practical 2** **Aim: Demonstrate various java inheritance using extends keyword.** **Source code:** // Single inheritance example class A {     void methodA() {         System.out.println(\"Method from class A\");     } } // Multilevel inheritance example class B extends A {     void methodB() {         System.out.println(\"Method from class B\");     } } // Hierarchical inheritance example class C extends A {     void methodC() {         System.out.println(\"Method from class C\");     } } class D extends B {     void methodD() {         System.out.println(\"Method from class D\");     } } public class InheritanceDemo {     public static void main(String\[\] args) {         // Single inheritance         A a = new A();         a.methodA();         // Multilevel inheritance         D d = new D();         d.methodA();         d.methodB();         d.methodD();         // Hierarchical inheritance         B b = new B();         b.methodA();         b.methodB();                 C c = new C();         c.methodA();         c.methodC();     } } **Output:**  **Practical 3** **Aim: Demonstrate polymorphism (Overriding) in java.** 1. Write a java program to create a class called shape with a method called getArea. Create a sub-class called rectangle that overrides the getArea method to calculate the area of rectangle. **Source code:** class Shape {     public int getArea(int l, int b)     {         return(0);     }   } class Rectangle extends Shape {     public int getArea(int l, int b)     {         return(l\*b);     }   } public class Areaofrec {     public static void main(String\[\] args)     {         Rectangle r = new Rectangle();         System.out.println(\"Area of rectangle is :\"+r.getArea(12,13));     } } **Output:** 2. Write a java program to create a class known as BankAccount with methods called deposit and withdraw. Create a sub-class called SavingAccount the overrides the withdraw method to prevent withdrawals if the account balance falls below 100. **Source code:** import java.util.Scanner; class BankAccount {     int amt=1000;     public void Deposit(int d)     {         amt+=d;         System.out.println(\"balance: \"+amt);     }     public void Withdraw()     {} } class SavingAccount extends BankAccount {     int Balance,wa;     Scanner sc;     public void Withdraw()     {         Balance=amt;         sc=new Scanner(System.in);         if(Balance\