HANDS ON JAVA(OOP - based uses) (Part-II)

           Practice JAVA like Never Before!

                                                                                                     courtesy: Google Images

Day 2 🔥

Objective

Learning to implement Classes, Objects, and Constructor concepts.

1. Add two floating-point numbers by taking input using java.util.Scanner class and java.io.BufferedReader class.

• Program

• Part 1:

//Firstly, we use java.util.Scanner class

import java.util.Scanner;

public class A2a{

    public static void main(String[] args){

        // Enter data using Scanner

        Scanner sc = new Scanner(System.in);

//message to the user:-

System.out.println("Enter two floating-point numbers:- ");

        float a = sc.nextFloat();

        float b = sc.nextFloat();

float sum = a+b;

        // Printing the sum

        System.out.println("The Sum is: "+sum);

    }

}

• Part 2:

//Next, we use java.io.BufferedReader class

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

public class A2b{

    public static void main(String[] args)throws IOException{

        // Enter data using BufferReader

        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));

        //message to the user:-

System.out.println("Enter two floating-point numbers:- ");

// Reading data using readLine

        float a = Float.parseFloat(reader.readLine());

        float b = Float.parseFloat(reader.readLine());

float sum = a+b;

        // Printing the read line

        System.out.println("The Sum is: "+sum);

    }

}

• Output:

• Part 1:

• Part 2:

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2. Write a program to find surface area and volume of Cylinder Using Constructor(s) - Keyboard Input or Command Line Input.

• Program:

class Cylinder{

public static double pi = 3.14159265359;
private double radius, height;
Cylinder(double r, double h){
radius = r;
height = h;
}
public double getSA(){
return 2*pi*radius*(radius+height);
}
public double getVolume(){
return pi*radius*radius*height;
}
public static void main(String[] args){
//accepting inputs as Command Line arguments
double rad = Double.parseDouble(args[0]);
double ht = Double.parseDouble(args[1]);
Cylinder cy; //declaring instance/object cy of class Cylinder
cy = new Cylinder(rad, ht); //instantiating cy, passing values as arguments to constructor
double area = cy.getSA(), volume = cy.getVolume();
System.out.println("The Surface Area of the Cylinder = "+area);
System.out.println("The Volume of the Cylinder = "+volume);
}
}//end class definition

 

• Output:

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3. Create a class named First, make instance variable [int x], instance method [void show()] and put main() method inside that class and use the instance variable and method from main().

• Program:

class First{

//Instance variable definition:-

public static int x = 10;

//Instance method definition:-

public static void show(){

System.out.print("x is: ");

}

//main method:-

public static void main(String[] args){

show();

if((x&1)==1)

System.out.println("ODD");

else

System.out.println("EVEN");

    }

}//end class

• Output:

--------------------------------------------------

4. Create a class; make its instance variable and instance method. Use them from main() which is declared in a different class.

• Program:

class First{

//Instance variable definition:-

public static int x = 135;

//Instance method definition:-

public static void show(){

System.out.print("x is: ");

}

}//end first class

class Test{

//main method:-

public static void main(String[] args){

First obj = new First();

obj.show();

if((obj.x&1)==1)

System.out.println("ODD");

else

System.out.println("EVEN");

}

}//end second class

• Output:

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<---------- End of Part - II ---------->😋