Area of different shapes

A program to calculate the area of different shapes (circle, triangle, 

rectangle, square) by using method overloading. 

Method Overloading:

              If a class has multiple methods by same name but different parameters, it is known as Method Overloading. If we have to perform only one operation, having same name of the methods increases the readability of the program. Suppose you have to perform addition of the given numbers but there can be any number of arguments, if you write the method such as a(int,int) for two parameters, and b (int,int,int) for three parameters then it may be difficult for you as well as other programmers to understand the behavior of the method because its name differs. So, we perform method overloading to figure out the program quickly.

Advantage of method overloading?

Method overloading increases the readability of the program.

Different ways to overload the method

There are two ways to overload the method in java

1. By changing number of arguments
2. By changing the data type

1) Method Overloading: changing no. of arguments

In this example, two methods are created, first add() method performs addition of two numbers and second add method performs addition of three numbers.

In this example, static methods are created so that don't need to create instance for calling methods.

1.                  class Adder{  

2.                  static int add(int a,int b){return a+b;}  

3.                  static int add(int a,int b,int c){return a+b+c;}  

4.                  }  

5.                  class TestOverloading1{  

6.                  public static void main(String[] args){  

7.                  System.out.println(Adder.add(11,11));  

8.                  System.out.println(Adder.add(11,11,11));  

9.                  }}  

Output :

22

33

2) Method Overloading: changing data type of arguments

In this example, two methods are created that differs in data type. The first add method receives two integer arguments and second add method receives two double arguments.

1.                  class Adder{  

2.                  static int add(int a, int b){return a+b;}  

3.                  static double add(double a, double b){return a+b;}  

4.                  }  

5.                  class TestOverloading2{  

6.                  public static void main(String[] args){  

7.                  System.out.println(Adder.add(11,11));  

8.                  System.out.println(Adder.add(12.3,12.6));  

9.                  }}  

Output :

22

24.9

Method Overloading is not possible by changing the return type of method only?

In java, method overloading is not possible by changing the return type of the method only because of ambiguity. Let's see how ambiguity may occur:

1.                  class Adder{  

2.                  static int add(int a,int b){return a+b;}  

3.                  static double add(int a,int b){return a+b;}  

4.                  }  

5.                  class TestOverloading3{  

6.                  public static void main(String[] args){  

7.                  System.out.println(Adder.add(11,11));//ambiguity  

8.                  }}  

Output :

Compile Time Error: method add(int,int) is already defined in class Adder

Algorithm:-

1.    

                 Start

2.      Define class Shape with its attributes and methods area() with different type and number of parameters.

3. Define class Demo
4. Create object of Shape class inside class Demo.
5. Call different overloaded area() methods using object of Shape.
6. Stop

Program :-

import java.util.Scanner;

class area

{

 public void area(int x)

   {

       System.out.println("area of square="+(x*x));

    }

     public void area(int x,int y)

   {

       System.out.println("area of rectangle="+(x*y));

    }

     public void area(double x)

   {

       System.out.println("area of circle="+(x*x*3.14));

    }

     public void area(double x,double y)

   {

       System.out.println("area of Triangle="+(x*y*0.5));

    }

}

class A1

{

public static void main(String args[])

{int i;

 Scanner s=new Scanner(System.in);

area w=new area();

do

{

System.out.println("<====Menu====>\n 1:area of rectangle\n 2:area of square\n 3:area of circle\n 4:area of Triangle\n 5:Exit");

 i=s.nextInt();

switch(i)

{

case 1:System.out.println("enter the value of length");

             int l=s.nextInt();

             System.out.println("enter the value of breadth");

              int b=s.nextInt();

               w.area(l ,b);

              break;

case 2: System.out.println("enter the value of side");

               int x= s.nextInt();

                  w.area (x);

               break;

case 3:  System.out.println("enter the value of radius");

               double e=s.nextDouble();

                w.area(e);

               break;

case 4:System.out.println("enter the value of base");

             double u=s.nextDouble();

             System.out.println("enter the value of height");

              double v=s.nextDouble();

               w.area(u ,v);

              break;

case 5:System.out.println("Thank you");

             break;

default:System.out.println("invlid choice");

             break;

}

}while(i!=5);

}

}

OUTPUT :-
<====Menu====>
 1:area of rectangle
 2:area of square
 3:area of circle
 4:area of Triangle
 5:Exit
1
enter the value of length
6
enter the value of breadth
8
area of rectangle=48
<====Menu====>
 1:area of rectangle
 2:area of square
 3:area of circle
 4:area of Triangle
 5:Exit
2
enter the value of side
5
area of square=25
<====Menu====>
 1:area of rectangle
 2:area of square
 3:area of circle
 4:area of Triangle
 5:Exit
3
enter the value of radius
4
area of circle=50.24
<====Menu====>
 1:area of rectangle
 2:area of square
 3:area of circle
 4:area of Triangle
 5:Exit
4
enter the value of base
3
enter the value of height
6
area of Triangle=9.0
<====Menu====>
 1:area of rectangle
 2:area of square
 3:area of circle
 4:area of Triangle
 5:Exit


     This is how you'll get the output, all you need to just enter the numbers from Menu list and implement your results. And here some observations, learning & conclusion over this program.

Observations and learning:  

Learned how to use method in java, and passing parameters to methods and and calling methods in java.Also learned the different return type of methods and learned the method overloading and use of method overloading.

Conclusion:  

By using method  overloading we achieve the  given problem. And learned the method overloading in java.