在 Java 中使用 Enum 的序数值索引数组是不好的做法吗? [英] Is it bad practice to use an Enum's ordinal value to index an array in Java?

问题描述

我有两个数组:Walls 和 Neighbors.

I have two arrays: Walls and Neighbors.

public boolean[] walls = new boolean[4];
public Cell[] neighbors = new Cell[4];

我有一个枚举:

enum Dir
{
    North,
    South,
    East,
    West
}

现在，我希望能够通过墙壁或邻居的方向访问它们，这样我就不必传递一堆魔法索引了.

Now, I would like to be able to access walls or neighbors by their direction, so I don't have to pass around a bunch of magic indexes.

然而，当我阅读 Enum.ordinal() 的文档时，它说程序员几乎不会使用这种方法，这让我觉得不应该以这种方式使用它.

However, when I was reading the documentation for Enum.ordinal() it said that programmers will have almost no use for this method which made me think it shouldn't be used in this way.

我正在考虑做类似的事情:

I was thinking of doing something like:

    List<Dir> availableDirections = new ArrayList<Dir>();
    for(Dir direction : Dir.values())
        if (!Neighbors[direction.ordinal()].Visited)
            availableDirections.add(direction);

甚至:

return Neighbors[Dir.North.ordinal()];

我应该恢复对 NORTH、SOUTH、EAST、WEST 使用静态常量并将索引值设置为它们还是使用 Enum 的序数方法?

Should I revert to using static constants for NORTH, SOUTH, EAST, WEST with the index value set to them or use an Enum's ordinal method?

推荐答案

在切线问题上，为您的邻居使用 EnumMap 可能会更好:

On a tangential issue, it might be better to use an EnumMap for your neighbours:

Map<Dir, Cell> neighbours = 
    Collections.synchronizedMap(new EnumMap<Dir, Cell>(Dir.class));

neighbours.put(Dir.North, new Cell());

for (Map.Entry<Dir, Cell> neighbour : neighbours.entrySet()) {
    if (neighbour.isVisited()) { ... }
}

etc..

顺便说一句:按照惯例，枚举实例应该全部大写，

BTW: Enum instances should by convention be all caps,

enum Dir {
    NORTH,
    EAST, 
    SOUTH,
    WEST
}

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