Data Access Method

Classic programmed-learning exercises, refreshed for modern Java and presented in the current MrStyner.com portfolio style.

Modern Java noteThis archive has been refreshed for Java 25 LTS. Core language concepts remain useful, while outdated setup instructions and browser-era Java are labeled or replaced. Java 26 is the current feature release; Java 25 is used here as the stable teaching baseline.

Answer:

Different values need to be stored in the object's x and yvariables.

Data Access Method

Here is the Circle class with two new methods. The setPosition() method will be used to change the location of a circle. The setRadius() method will be used to change the radius of a circle. Such methods are called access methods because they access the data of an object. Well-designed classes allow access to their data only through access methods. To enforce this, the variables of a class are often made private.

class Circle
{
  // variables
  private int x, y, radius;

  // constructors
  public Circle()
  { x = 0; y = 0; radius = 0; }

  public Circle( int x, int y, int radius )
  { this.x = x;  this.y = y;  this.radius = radius; }

  // methods
  void draw( Graphics gr )
  {
    int ulX = x-radius ; // X of upper left corner of rectangle
    int ulY = y-radius ; // Y of upper left corner of rectangle
    gr.drawOval( ulX, ulY, 2*radius, 2*radius );
  }

  // change the center of the circle to a new X and Y
  void setPosition( int newX, int newY )
  {
     ;

     ;
  }

  // chage the radius of the circle
  void setRadius( int newR )
  {

     ;
  }

}

QUESTION 9:

Complete the methods by filling in the blanks.