我可以为Enum创建构造函数吗? [英] Can I create constructor for Enum?

问题描述

我已经编写了以下代码，并且编译成功.

I have written below code and it's compiling successfully.

class Program
{
        enum Fruits
        {
            Apple,
            Mango,
            Banana
        }

        static void Main(string[] args)
        {
            Fruits f = new Fruits();
        }
}

尽管 Fruits 是 enum ，但编译器和解释器允许我编写此代码.这是否意味着我可以为枚举创建构造函数?如果是，那怎么办?

Despite of Fruits being an enum, compiler and interpreter are allowing me to write this. Does this mean I can create a constructor for an enum? if yes then how?

推荐答案

不，你不能.

new Fruits()将返回默认值(对应于枚举的基础类型中 0 的值)，它与 default(水果)(或您的案例中的 Fruits.Apple ).

new Fruits() will return the default value (the value corresponding to 0 in the underlying type of the enum), it's the same as default(Fruits) (or Fruits.Apple in your case).

请记住，枚举仅是原始类型(默认情况下为 int )的包装.您几乎可以将 new Fruits()与 new int()进行比较.

Remeber that enums are only wrappers around a primitive type (int by default). You can pretty much compare new Fruits() to new int().

通常，您不使用 new Fruits()/ new int()语法，因为通常只写 0 或 default(T)，但您可能需要在通用代码中使用它.例如:

Usually you don't use the new Fruits()/new int() syntax as it's more common to just write 0 or default(T), but you may want to use it in generic code. As an example:

public T NewInstance<T>()
    where T : new()
{
    return new T();
}

允许您调用 NewInstance< Fruits>()，这将返回 Fruits.Apple .

You are allowed to call NewInstance<Fruits>(), which will return Fruits.Apple.

这篇关于我可以为Enum创建构造函数吗?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！