java - 点 isAbove, isUnder, isRight, isLeft 方法

Question

这是我的积分等级；

public class Point
{
    private int _x;
    private int _y;

    public boolean isAbove (Point other)
    {
        if (_y <= other._y)
            return false;
        else
            return true;
    }

    public boolean isUnder (Point other)
    {
        return isAbove(other);
    }

    public boolean isLeft (Point other)
    {
        if (_x >= other._x)
            return false;
        else
            return true;
    }

    public boolean isRight (Point other)
    {
        return isLeft(other);
    }
}

以上所有方法都没有按预期运行，我找不到我做错了什么。例如:

Point pp1 = new Point(1, 0);
Point pp2 = new Point(0, 0);
System.out.println("isAbove: " + pp1.isAbove(pp2));
System.out.println("isUnder: " + pp1.isUnder(pp2));
System.out.println("isLeft : " + pp1.isLeft(pp2));
System.out.println("isRight: " + pp1.isRight(pp2));

全部返回false。

Answer 1

试试这个，它应该工作:

public boolean isAbove (Point other)
{
    return _y > other._y;       
}

public boolean isUnder (Point other)
{
    return other.isAbove(this);
}

public boolean isLeft (Point other)
{
    return _x < other._x;
}

public boolean isRight (Point other)
{
    return other.isLeft(this);
}