究竟为什么使用数组，而不是一个哈希？ [英] Why ever use an array instead of a hash?

问题描述

我已阅读，这是更快通过散列迭代不是通过一个数组。从散列检索值也快多了。

I have read that it is much faster to iterate through a hash than through an array. Retrieving values from a hash is also much faster.

而不是使用一个数组，为什么不使用哈希，并给每个键对应的索引值？如果项永远需要处于顺序，它们可以被排序。

Instead of using an array, why not just use a hash and give each key a value corresponding to an index? If the items ever need to be in order, they can be sorted.

推荐答案

从哈希检索中，你可以通过直接键获取，而不是遍历整个哈希（或数组价值感快，当你正在寻找特定字符串）。有了这样的说， $ {哈希键} 不大于 $阵列更快[0] 因为没有迭代正在的地方。

Retrieving from hash is faster in a sense that you can fetch value directly by key instead of iterating over whole hash (or array when you're searching for particular string). Having that said, $hash{key} isn't faster than $array[0] as no iteration is taking place.

阵列无法通过哈希来代替，因为它们各有特点，

Arrays can't be replaced by hashes, as they have different features,

                       arrays hashes
------------------------------------
ordered keys            x       -
push/pop                x       -
suitable for looping    x       -
named keys              -       x

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