Java program to calculate Area of Circle
Java program to calculate the Area of Circle
Write a Java program to calculate the Area of the Circle. On this page, we will write a Java program to calculate the area of the circle. Before writing the program we will analyze the IPO of the program.
IPO Chart
Input: The data, resources, etc that enter the system.
Process: The actions, operations, or calculations that transform inputs into outputs by the program.
Output: The final results, and outputs produced by the system.
Input
The radius of the circle
Process
Area of Circle = pi * r * r
Output
Area of Circle
Java Program
import java.util.Scanner;
/**************************************************
* CircleDemo.java
* @program : Area of Circle
* @web : www.TestingDocs.com
* @author :
* @version : 1.0
**************************************************/
public class CircleDemo {
//main
public static void main(String[] args) {
Scanner keyboard = new Scanner(System.in);
double radius, areaCircle;
System.out.print("Enter Radius of the Circle := ");
radius = keyboard.nextDouble();
// formula = pi r square
areaCircle = Math.PI*radius*radius;
System.out.println("Area of Circle = "+ areaCircle);
keyboard.close();
} // end main
} // end CircleDemo
Sample Output
Sample output of the program is as follows:
Enter Radius of the Circle := 3.5
Area of Circle = 38.48451000647496
Screenshot
Screenshot of the program in the IDE.

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