为什么字典在 C# 中优于 Hashtable?

Why is Dictionary preferred over Hashtable in C#?(为什么字典在 C# 中优于 Hashtable?)

问题描述

在大多数编程语言中，字典比哈希表更受欢迎.背后的原因是什么?

In most programming languages, dictionaries are preferred over hashtables. What are the reasons behind that?

推荐答案

就其价值而言，字典是(概念上)一个哈希表.

For what it's worth, a Dictionary is (conceptually) a hash table.

如果您的意思是为什么我们使用 Dictionary 类而不是 Hashtable 类?"，那么答案很简单:Dictionary 是泛型类型，Hashtable 不是.这意味着您可以使用 Dictionary<TKey, TValue> 获得类型安全，因为您不能将任何随机对象插入其中，并且您不必强制转换取出的值.

If you meant "why do we use the Dictionary<TKey, TValue> class instead of the Hashtable class?", then it's an easy answer: Dictionary<TKey, TValue> is a generic type, Hashtable is not. That means you get type safety with Dictionary<TKey, TValue>, because you can't insert any random object into it, and you don't have to cast the values you take out.

有趣的是，.NET Framework 中的 Dictionary 实现是基于 Hashtable 的，从源代码中的这条注释可以看出:

Interestingly, the Dictionary<TKey, TValue> implementation in the .NET Framework is based on the Hashtable, as you can tell from this comment in its source code:

通用字典是从 Hashtable 的源中复制的

The generic Dictionary was copied from Hashtable's source

来源

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