检查数组中是否有咖啡脚本中的某些项目 [英] Checking if an array has some items in coffeescript

问题描述

当数组中有一些项目时，coffeescript 中是否有一些方法返回 true?像 ruby​​ 中的方法 present?:

Is there some method in coffeescript that returns true when an array has some items in it? Like method in ruby present?:

[].present? false
[1].present? true

根据http://arcturo.github.com/library/coffeescript/07_the_bad_parts.htmlcoffeescript 中的数组空性由它的长度决定

According to http://arcturo.github.com/library/coffeescript/07_the_bad_parts.html an array emptiness in coffeescript is determined by its length

alert("Empty Array")  unless [].length

这对我来说太蹩脚了.

推荐答案

我认为没有但可以:

Array::present = ->
  @.length > 0

if [42].present()
  # why yes of course
else
  # oh noes

一个非常简单和不完整的实现，但它应该给你一些想法.并且记录一下，Ruby 中没有 present? 方法，该方法是由 active_support gem 添加的.

A very simple and incomplete implementation but it should give you some ideas. And for the record, there's no present? method in Ruby, the method is added by the active_support gem.

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