programming-examples/java/_Basics/Program to Calculate Circle Area (Java).java
2019-11-15 12:59:38 +01:00

51 lines
1.5 KiB
Java

/*
Calculate Circle Area using Java Example
This Calculate Circle Area using Java Example shows how to calculate
area of circle using it's radius.
*/
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
public class CalculateCircleAreaExample
{
public static void main(String[] args)
{
int radius = 0;
System.out.println("Please enter radius of a circle");
try
{
//get the radius from console
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
radius = Integer.parseInt(br.readLine());
}
//if invalid value was entered
catch(NumberFormatException ne)
{
System.out.println("Invalid radius value" + ne);
System.exit(0);
}
catch(IOException ioe)
{
System.out.println("IO Error :" + ioe);
System.exit(0);
}
/*
* 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);
}
}
/*
Output of Calculate Circle Area using Java Example would be
Please enter radius of a circle
19
Area of a circle is 1134.1149479459152
*/