En este tutorial veremos cómo calcular el área y la circunferencia del círculo en Java. Hay dos maneras de hacer esto:
1) Con la interacción del usuario: el programa le pedirá al usuario que ingrese el radio del círculo.
2) Sin interacción del usuario: el valor del radio se especificaría en el propio programa.
Programa 1:
/**
* @author: BeginnersBook.com
* @description: Program to calculate area and circumference of circle
* with user interaction. User will be prompt to enter the radius and
* the result will be calculated based on the provided radius value.
*/
import java.util.Scanner;
class CircleDemo
{
static Scanner sc = new Scanner(System.in);
public static void main(String args[])
{
System.out.print("Enter the radius: ");
/*We are storing the entered radius in double
* because a user can enter radius in decimals
*/
double radius = sc.nextDouble();
//Area = PI*radius*radius
double area = Math.PI * (radius * radius);
System.out.println("The area of circle is: " + area);
//Circumference = 2*PI*radius
double circumference= Math.PI * 2*radius;
System.out.println( "The circumference of the circle is:"+circumference) ;
}
}
Producción:
Enter the radius: 1 The area of circle is: 3.141592653589793 The circumference of the circle is:6.283185307179586
Programa 2:
/**
* @author: BeginnersBook.com
* @description: Program to calculate area and circumference of circle
* without user interaction. You need to specify the radius value in
* program itself.
*/
class CircleDemo2
{
public static void main(String args[])
{
int radius = 3;
double area = Math.PI * (radius * radius);
System.out.println("The area of circle is: " + area);
double circumference= Math.PI * 2*radius;
System.out.println( "The circumference of the circle is:"+circumference) ;
}
}
Producción:
The area of circle is: 28.274333882308138 The circumference of the circle is:18.84955592153876