Question

我有一个包含一堆代码的段类。我一直坚持使用两种方法，isParallel和缩短方法。这是我到目前为止的代码（我有一个与此类相关联的点类）：

＆＃13 ;

＆＃13;

  public class Segment {

	//two Points that hold endpoints of the segment
	private Point p1, p2;
	
	
	//Default constructor that will set the endpoints to new
	//Points with values (0,0) and (4,4)
	public Segment(){
		this(0, 0, 4, 4);
	}
	
	//Parameterized constructor that accepts (int x1, int y1, int x2, int y2)
	//and creates and sets the endpoints
	public Segment(int x1, int x2, int y1, int y2){
		this.p1 = new Point(x1, y1);
		this.p2 = new Point(x2, y2);
	}
	
	//Parameterized constructor that accepts (Point p1, Point p2) and sets both
	//the endpoints to a deep copy of the Points that are passed in.
	public Segment( Point p1, Point p2){
		this.p1 = new Point(p1.getX(), p1.getY());
		this.p2 = new Point(p2.getX(), p2.getY());
	}
	
	//Copy constructor that accepts a Segment and initializes the data (of the
	//new Segment being created) to be the same as the Segment that was received.
	public Segment(Segment other){
		p1 = other.getP1();
		p2 = other.getP2();
	}

	public Point getP1(){
		return p1;
	}
	
	public Point getP2(){
		return p2;
	}
	
	//The length method returns the length of the Segment.In fact, this method is same as distanceTo method
	//So we can use distanceTo method which is already defined in Point class
	public double length(){
		return (p1.distanceTo(p2));
	}
	
	//The translate method returns nothing and should translate, or shift,	
	//itself (the Segment) by the distances passed in
	public void translate(int xmove, int ymove) {
	        p1.translate(xmove,ymove);
	        p2.translate(xmove,ymove);
	 }
	
	//The midpoint method calculates and returns the midpoint of the Segment as a new Point
	public Point midpoint(){
		return (p1.halfWayTo(p2));	
	}
	
	//The slope method returns the slope of the Segment as a double.
	public double slope(){
			return (double)(p2.getY() - p1.getY()) / (p1.getX() - p2.getX());
	}


	/**
	 * The isParallel method returns true/false depending on whether the current Segment
	 * is parallel to the Segment received.   Think about how you can tell if two segments
	 * are parallel.  Note: Two overlapping segments ARE parallel.
	 */
	 public boolean isParallel( Segment s1 ){

  
{
    
  /**
	 * The shorten method changes its (the Segment's) endpoints so that they are both halfway
	 * to the midpoint. Example: The segment (0,0)---(12,16) has midpoint (6,8).  After
	 * calling the shorten method, the segment should be (3,4)---(9,12).  Each endpoint
	 * has moved in toward the midpoint (which stayed the same).  So (3,4) is halfway between
	 * (0,0) and (6,8) and (9,12) is halfway between (12,16) and (6,8).
	 */
    public void shorten();

＆＃13;

有人可以让我知道如何在我的代码中使用这两种方法。我非常感谢你的帮助。

谢谢！

Answer 1

我实际上在完成同样的任务！对于isParallel方法，您需要检查并查看当前Segment的斜率是否与收到的Segment的斜率相同。我还没有采用缩短方法，所以我无法帮助你。

另外，在我的课堂上（因为我做同样的任务），我们不能使用getX()和getY()方法，因为它们会破坏整个目的学习封装。我们需要实际要求Point类计算点的信息。例如，使用斜率方法而不是返回return (double)(p2.getY() - p1.getY()) / (p1.getX() - p2.getX());，我在Point内部创建了一个方法来计算称为calcSlope的两个点的斜率。并在细分中Slope方法内调用该方法：return p1.calcSlope(p2);。

希望这有帮助！

如何在段类中使用isParallel和缩短方法？

1 个答案: