Java double type

Introduction

Java double type uses 64 bits to store a value.

All transcendental math functions in Java, such as sin(), cos(), and sqrt(), return double values.

Here is a short program that uses double variables to compute the area of a circle: 

// Compute the area of a circle.
public class Main {
  public static void main(String args[]) {
    double pi, r, a; 

    r = 10.8; // radius of circle
    pi = 3.1416; // pi, approximately
    a = pi * r * r; // compute area

    System.out.println("Area of circle is " + a);
  }/*  w  ww .ja v  a  2  s.c  o m*/
}

Java double type calculate area of circle 

public class Main
{

  public static void main( String[] args )
  {//  w  w w.j a  va  2s  .  c o m
    java.util.Scanner input = new java.util.Scanner( System.in );

    
    System.out.print( "Enter to radius: " );
    double radius = input.nextDouble();
    
    System.out.printf( "The area is: %.2f%n", circleArea( radius ) );
  }
  
  public static double circleArea( double radius )
  {
    return Math.PI * Math.pow( radius, 2 );
  }

}



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