1. Program to Print Hello World.

class HelloWorld
{
public static void main(String args[])
{
System.out.println("Hello World!!");
}
}

@java_codings

2. Program to Accept values of Two Numbers and print their Addition.

import java.util.Scanner;

class AddNumbers
{
public static void main(String args[])
{
int x, y, z;
System.out.print("Enter two integers to calculate their sum : ");
Scanner in = new Scanner(System.in);
x = in.nextInt();
y = in.nextInt();
z = x + y;
System.out.println("Sum of entered integers = " + z);
}
}

@java_codings

3. Program to accept three Number and Print Largest among them.

class CommandLineArgs

{
public static void main(String args[])
{
int a, b, c;

a = Integer.parseInt(args[0]);
b = Integer.parseInt(args[1]);
c = Integer.parseInt(args[2]);

if (a > b && a > c) {
System.out.println("Largest Number is : " + a);
} else if (b > c) {
System.out.println("Largest Number is : " + b);
} else {
System.out.println("Largest Number is : " + c);
}
}
}

@java_codings

4. Program to Accept value of Radius and Calculate Area of Circle.

class CalculateCircleAreaExample
{

public static void main(String[] args)
{

int radius = 3;
System.out.println("The radius of the circle is " + radius);

/*
* Area of a circle is pi * r * r where r is a radius of a circle.
*/

// NOTE : use Math.PI constant to get value of pi
double area = Math.PI * radius * radius;

System.out.println("Area of a circle is " + area);
}
}

@java_codings

5. Program to Accept value of length & width and Calculate Area of Rectangle.

import java.util.Scanner;

class AreaOfRectangle
{
public static void main(String[] args)
{
Scanner scanner = new Scanner(System.in);

System.out.println("Enter the length of Rectangle:");
double length = scanner.nextDouble();

System.out.println("Enter the width of Rectangle:");
double width = scanner.nextDouble();

//Area = length*width;
double area = length * width;

System.out.println("Area of Rectangle is:" + area);
}
}

@java_codings

6. Program to Accept value of the side of Square and Calculate Area of Square.

import java.util.*;

class AreaOfSquare
{
public static void main(String args[])
{
int side, area;

Scanner sc = new Scanner(System.in);

System.out.println("Enter value of the sides of square");
side = sc.nextInt();

area = side * side;

System.out.println("Area of Square : " + area);
}
}

@java_codings

7. Program to Calculate Area's.

import java.util.Scanner;

class AreaCalculator
{

float l, b, h, r, ba, s, c;
float result = 0f;
float pi = 3.14f;
int var;
public static void main(String[] args)
{
AreaCalculator ar = new AreaCalculator();
ar.options();
}

public void options()
{
Scanner a = new Scanner(System.in);
System.out.println("Enter the Object of which Area is to be calculated \n1:square \n2:rectangle \n3:Triangle\n4:circle\n5:Trapezoid\n6:Repeat\n7:Exit");

var = a.nextInt();
Area a1 = new Area();

if (var == 1)
{
System.out.println("Enter the Side of Square");
s = a.nextFloat();
a1.square(s);
options();
}

else if (var == 2)
{
System.out.println("Enter the Length of Rectangle");
l = a.nextFloat();
System.out.println("Enter the Breadth of Rectangle");
b = a.nextFloat();
a1.rectangle(l, b);
options();
}

else if (var == 3)
{
System.out.println("Enter the Height of Triangle");
h = a.nextFloat();
System.out.println("Enter the Base of Triangle");
ba = a.nextFloat();
a1.triangle(h, ba);
options();
}

else if (var == 4)
{
System.out.println("Enter the Radius of Circle");
r = a.nextFloat();
a1.circle(r);
options();
}

else if (var == 5)
{
System.out.println("Enter the A side of Trapezoid");
b = a.nextFloat();
System.out.println("Enter the B side of Trapezoid");
c = a.nextFloat();
System.out.println("Enter the Height of Trapezoid");
h = a.nextFloat();
a1.trapezoid(b, c, h);
options();
}
}
}

class Area
{
public void square(float s)
{
float result = 0f;
result = s * s;
System.out.println("The Area of Square is :" + result);
}

public void rectangle(float l, float b)
{
float result = 0f;
result = l * b;
System.out.println("The Area of Rectangle is :" + result);
}

public void triangle(float h, float ba)
{
float result = 0f;
result = 0.5f * h * ba;
System.out.println("The Area of Triangle is :" + result);
}

public void circle(float r)
{
float result = 0f;
result = 3.14f * (r * r);
System.out.println("The Area of Circle is :" + result);
}

public void trapezoid(float b, float c, float h)
{
float result = 0f;
result = (((b + c) / 2) * h);
System.out.println("The Area of Trapezoid is :" + result);
}
}

@java_codings