testcirclewithprivatemodifier.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。

// TestCircleWithPrivateModifier.java: Demonstrate private modifier
public class TestCircleWithPrivateModifier
{
  // Main method
  public static void main(String[] args)
  {
    // Create a Circle with radius 5.0
    Circle myCircle = new Circle(5.0);
    System.out.println("The area of the circle of radius "
      + myCircle.getRadius() + " is " + myCircle.findArea());

    // Increase myCircle's radius by 10%
    myCircle.setRadius(myCircle.getRadius()*1.1);
    System.out.println("The area of the circle of radius "
      + myCircle.getRadius() + " is " + myCircle.findArea());
  }
}
/*
// Declare class Circle with private radius and accessor methods
class Circle
{
  private double radius;

  // Default constructor
  public Circle()
  {
    radius = 1.0;
  }

  // Construct a circle with a specified radius
  public Circle(double r)
  {
    radius = r;
  }

  // Getter method for radius
  public double getRadius()
  {
    return radius;
  }

  // Setter method for radius
  public void setRadius(double newRadius)
  {
    radius = newRadius;
  }

  // Find the circle area
  public double findArea()
  {
    return radius*radius*3.14159;
  }
}
*/