computearea.java

此源码为机械工业出版社出版的《Java语言程序设计》第三版所配套的书中所有源代码。

// ComputeArea.java: Compute the area of a circle
public class ComputeArea
{
  // Main method
  public static void main(String[] args)
  {
    double radius;
    double area;
    final double PI = 3.14159; // Declare a constant

    // Prompt the user to enter radius
    System.out.print("Enter radius: ");
    radius = MyInput.readDouble();

    // Compute area
    area = radius*radius*PI;

    // Display results
    System.out.println("The area for the circle of radius " +
      radius + " is " + area);
  }
}