在 Ruby on Rails html.erb 文件中循环
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Loop in Ruby on Rails html.erb file
提问by Stark_kids
everybody I'm brand new with Ruby on Rails and I need to understand something. I have an instance variable (@users) and I need to loop over it inside an html.erb file a limitated number of times. I already used this:
我是 Ruby on Rails 的新手，我需要了解一些东西。我有一个实例变量 (@users)，我需要在 html.erb 文件中循环遍历它有限的次数。我已经用过这个：
<% @users.each do |users| %>
<%= do something %>
<%end %>
But I need to limitate it to, let's say, 10 times. What can I do?
但我需要将其限制为，比如说，10 次。我能做什么？
回答by infused
If @usershas more elements than you want to loop over, you can use firstor slice:
如果@users元素多于您想要循环的元素，您可以使用first或slice：
Using first
使用 first
<% @users.first(10).each do |users| %>
<%= do something %>
<% end %>
Using slice
使用 slice
<% @users.slice(0, 10).each do |users| %>
<%= do something %>
<% end %>
However, if you don't actually need the rest of the users in the @users array, you should only load as many as you need by using limit:
但是，如果您实际上不需要@users 数组中的其余用户，则应该只加载所需数量的用户limit：
@users = User.limit(10)
回答by Santhosh
You could do
你可以做
<% for i in 0..9 do %>
<%= @users[i].name %>
<% end %>
But if you need only 10 users in the view, then you can limit it in the controller itself
但是如果视图中只需要 10 个用户，那么您可以在控制器本身中对其进行限制
@users = User.limit(10)
回答by Mohamed El Mahallawy
Why don't you limit the users?
为什么不限制用户？
<%= @users.limit(10).each do |user| %>
...
<%end%>
That'd still use ActiveRecord so you get the benefit of AR functions. You can also do a number of things too such as:
那仍然会使用 ActiveRecord，因此您可以获得 AR 功能的好处。您还可以做很多事情，例如：
@users.first(10)or @users.last(10)
@users.first(10)或者 @users.last(10)
