什么是＆QUOT;右QUOT;这样，通过在Ruby中数组循环？ [英] What is the "right" way to iterate through an array in Ruby?

问题描述

PHP，其所有疣，是pretty这个算不错。有一个数组和哈希（也许我幼稚，但是这似乎很明显我的权利）没有什么区别，并可通过你只是做迭代

PHP, for all its warts, is pretty good on this count. There's no difference between an array and a hash (maybe I'm naive, but this seems obviously right to me), and to iterate through either you just do

foreach (array/hash as $key => $value)

在Ruby中有一堆的方式做这样的事情：

In Ruby there are a bunch of ways to do this sort of thing:

array.length.times do |i|
end

array.each

array.each_index

for i in array

哈希更有意义，因为我只是总是用

Hashes make more sense, since I just always use

hash.each do |key, value|

为什么我不能数组做到这一点？如果我要记住只有一个方法，我想我可以使用 each_index （因为它使双方指数和价值提供），但它很烦人要做数组[索引] ，而不是仅仅值。

Why can't I do this for arrays? If I want to remember just one method, I guess I can use each_index (since it makes both the index and value available), but it's annoying to have to do array[index] instead of just value.

哦，对了，我忘了 array.each_with_index 。然而，这一次吮吸，因为它会 |价值，关键| 和 hash.each 进入 |键，值| ！这是不是疯了？

Oh right, I forgot about array.each_with_index. However, this one sucks because it goes |value, key| and hash.each goes |key, value|! Is this not insane?

推荐答案

这将通过所有的元素迭代：

This will iterate through all the elements:

array = [1, 2, 3, 4, 5, 6]
array.each { |x| puts x }

打印：

1
2
3
4
5
6

这将通过所有元素迭代给你的价值和指数：

This will iterate through all the elements giving you the value and the index:

array = ["A", "B", "C"]
array.each_with_index {|val, index| puts "#{val} => #{index}" }

打印：

A => 0
B => 1
C => 2

我不是从你的问题哪一个你正在寻找非常肯定。

I'm not quite sure from your question which one you are looking for.

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