Question

I have two models: 22 55 and class User < ActiveRecord::Base. If I write:

class Tips < ActiveRecord::Base

or

user.each do |...|

Should I treat either as an array or a hash? How will I know?

I would post the model for user and tips, but they are very long. Any help is appreciated! Thanks in advance!!!

Answer 1

Objects inheriting from update tracks set album_id = a.id from albums a where tracks.album_name = a.name are ActiveRecord Objects and should be treated as such. A comprehensive list of methods can be found here. You can optionally convert AR objects to arrays (using the ActiveRecord::Base built-in) or hashes (by using your own hash implementation depending on how you want the keys and values)

Answer 2

我认为你的问题可以通过多种方式得到改善。如果我理解正确：

你有一个班级

class User < ActiveRecord::Base
  has_many :tips
  ...
end

class Tip < ActiveRecord::Base
  belongs_to :user
  ...
end

所以如果你有一个Tip类的实例（该类应该是单数，除非这个类的每个实例代表许多提示） - 让我们调用这个实例@tip - 它只属于一个用户。所以@tick.user将真的是这个用户 - 没有什么可以迭代（没有像哈希或数组）。但用户本身有很多提示。所以@ user.tips就像一个数组。虽然@ user.tips不是一个数组（只需在rails控制台中尝试类似：

@user = User.first
@user.tips.class

），它在大多数情况下表现得像一个数组。如果你需要一个真正的数组，你可以使用

@user.tips.to_a

但在大多数情况下，你应该坚持协会本身。

Answer 3

For what it seems you're trying to do, treat it as an array. In fact, you can do LayoutInflator's inflate(), and it'll be an array.

Answer 4

Programming languages vary as to their exact meaning of "array" vs. "hash," but Ruby (unlike PHP, say ...) follows Perl:

A "hash" is a collection of things, indexed by an arbitrary "key."
An "array" is an ordered collection of things, indexed by an integer.

Therefore, "what makes the most sense, for you, in this case?" If "this collection-of-things is naturally 'ordered,' such that the "most comfy" way to think of it is "#1, #2, #3 ...," then a Ruby <table id="users-table" class="table table-hover table-striped"> <thead> <tr> <th>#</th> <th>First Name</th> <th>Last Name</th> </tr> </thead> </table> $(function() { $('#users-table').dataTable({ ajax: '@Url.Action("ListUsers", "Businesses",null,Request.Url.Scheme)' }); }); would be called for. Whereas, if one would (instead) ordinarily think of, "the entry for 'Tom,' 'Dick,' or 'Harry,'" the best representation would be a array.

Superficially, since I see no obvious "key," the best answer is probably: an hash.

Do I treat this as an array or a hash?

4 个答案: