Using Classes and Objects - Java Software Solutions: Foundations of Program Design - page 136

LISTING 3.5
//********************************************************************
// CircleStats.java Author: Lewis/Loftus
//
// Demonstrates the formatting of decimal values using the
// DecimalFormat class.
//********************************************************************
import java.util.Scanner;
import java.text.DecimalFormat;
public class CircleStats
{
//-----------------------------------------------------------------
// Calculates the area and circumference of a circle given its
// radius.
//-----------------------------------------------------------------
public static void main (String[] args)
{
int radius;
double area, circumference;
Scanner scan = new Scanner (System.in);
System.out.print ("Enter the circle's radius: ");
radius = scan.nextInt();
area = Math.PI * Math.pow(radius, 2);
circumference = 2 * Math.PI * radius;
// Round the output to three decimal places
DecimalFormat fmt = new DecimalFormat ("0.###");
System.out.println ("The circle's area: " + fmt.format(area));
System.out.println ("The circle's circumference: "
+ fmt.format(circumference));
}
}
OUTPUT
Enter the circle's radius: 5
The circle's area: 78.54
The circle's circumference: 31.416