// A very simple class that defines a cartesian point, and has a translate // method, a constructor, and a toString() method public class Point4 { int x; // an "instance variable" defining the point's x value int y; // an "instance variable" defining the point's y value // a constructor method for a Point object public Point4(int x, int y) { this.x = x; this.y = y; } // this method translates the point by (dx, dy) public void translate(int dx, int dy) { this.x += dx; // "this" is a reference to the object instance this.y += dy; // whose translate method was invoked } // a more useful toString() method to print the Point's value public String toString() { return "(" + this.x + ", " + this.y + ")"; } }