遍历数组的每个元素(第一个元素除外) [英] Iterating over each element of an array, except the first one

问题描述

Ruby编写此代码的惯用方式是什么?

What is the idiomatic Ruby way to write this code?

给出一个数组，我想遍历该数组的每个元素，但是跳过第一个.我想这样做而不分配新数组.

Given an array, I would like to iterate through each element of that array, but skip the first one. I want to do this without allocating a new array.

这是我想出的两种方法，但都不是特别优雅.

Here are two ways I've come up with, but neither feels particularly elegant.

这可行，但似乎太冗长了:

This works but seems way too verbose:

arr.each_with_index do |elem, i|
  next if i.zero? # skip the first
  ...
end

这有效，但是分配了一个新数组:

This works but allocates a new array:

arr[1..-1].each { ... }

编辑/说明:我想避免分配第二个数组.最初，我说过我想避免复制"该数组，这很令人困惑.

推荐答案

使用内部枚举器肯定更直观，并且您可以像这样相当优雅地完成此操作:

Using the internal enumerator is certainly more intuitive, and you can do this fairly elegantly like so:

class Array
  def each_after(n)
    each_with_index do |elem, i|
      yield elem if i >= n
    end
  end
end

现在:

arr.each_after(1) do |elem|
  ...
end

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