Using Objects : Declare Object « Class Definition « Java Tutorial

1. Java Tutorial
2. Class Definition
3. Declare Object

class Point {
  double x;

  double y;

  Point(double xVal, double yVal) {
    x = xVal;
    y = yVal;
  }

  Point(final Point oldPoint) {
    x = oldPoint.x;
    y = oldPoint.y;
  }

  void move(double xDelta, double yDelta) {
    x += xDelta;
    y += yDelta;
  }

  double distance(final Point aPoint) {
    return Math.sqrt((x - aPoint.x) * (x - aPoint.x) + (y - aPoint.y) * (y - aPoint.y));
  }

  public String toString() {
    return Double.toString(x) + ", " + y;
  }
}

// You can use Point objects in the definition of the class Line:

class Line {
  Point start;

  Point end;

  Line(final Point start, final Point end) {
    this.start = new Point(start);
    this.end = new Point(end);
  }

  Line(double xStart, double yStart, double xEnd, double yEnd) {
    start = new Point(xStart, yStart);
    end = new Point(xEnd, yEnd);
  }

  double length() {
    return start.distance(end);
  }

  public String toString() {
    return "(" + start + "):(" + end + ")";
  }
}


public class MainClass{
  public static void main(String[] arg){
    Line l1 = new Line(new Point(1,2), new Point(3,4));
    
    System.out.println(l1);
  }
  
}

(1.0, 2.0):(3.0, 4.0)