双型比较器 [英] Comparator with double type

问题描述

我编写了以下代码:

public class NewClass2 implements Comparator<Point>
{
    public int compare(Point p1, Point p2)
    {
        return (int)(p1.getY() - p2.getY());
    }
}

如果我假设有两个双数，3.2 - 3.1，差异应该是 0.1.然而，当我将数字转换为 int 时，差异最终为 0，这是不正确的.

If I let's say have two double numbers, 3.2 - 3.1, the difference should be 0.1. When I cast the number to an int, however, the difference ends up as 0, which is not correct.

因此我需要 compare() 返回双精度值，而不是整数.问题是，我的 getX 字段是双精度的.我该如何解决这个问题?

I therefore need compare() to return a double, not an int. The problem is, my getX field is a double. How can I solve this problem?

推荐答案

不需要返回double.

Comparator 接口用于为被比较的元素建立排序.使用 double 的字段与此顺序无关.

The Comparator interface is used to establish an ordering for the elements being compared. Having fields that use double is irrelevant to this ordering.

你的代码没问题.

抱歉，我错了，再次阅读问题，这就是您所需要的:

Sorry, I was wrong, reading the question again, this is what you need:

public class NewClass2 implements Comparator<Point> {
    public int compare(Point p1, Point p2) {
        if (p1.getY() < p2.getY()) return -1;
        if (p1.getY() > p2.getY()) return 1;
        return 0;
    }    
}

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