CODEWITHSUNDEEP
ruby-on-rails
alamodey
alamodey

Reputation: 14938

How to determine last object in each loop?

In your typical each loop in Rails, how do I determine the last object, because I want to do something different to it than the rest of the objects.

<% @stuff.each do |thing| %>

<% end %>

Upvotes: 41

Views: 34472

Answers (6)

Arian Faurtosh
Arian Faurtosh

Reputation: 18491

Surprised this is not listed as an answer, but to my this is the cleanest way to do it. By starting the index at 1, you can remove the math of making the index and size match up.

@stuff = [:first, :second, :last]

@stuff.each.with_index(1) do |item, index|
  if index == @stuff.size
    # last item
  else
    # other items
  end
end

also the added benefit here is that you can use this on the .map as well.

Upvotes: 1

abject_error
abject_error

Reputation: 2938

@stuff.each do |s|
  ...normal stuff...
  if s == @stuff.last
    ...special stuff...
  end
end

Upvotes: 67

jackpipe
jackpipe

Reputation: 981

<% @stuff[0...-1].each do |thing| %>
  <%= thing %>
<% end %>
<%= @stuff.last %>

Upvotes: 8

A.Ali
A.Ali

Reputation: 749

Interesting question. Use an each_with_index.

len = @stuff.length

@stuff.each_with_index do |x, index|
 # should be index + 1       
 if index+1 == len
 # do something
  end
end

Upvotes: 33

Sam
Sam

Reputation: 1014

A more lispy alternative is to be to use

@stuff[1..-1].each do |thing|

end
@stuff[-1].do_something_else

Upvotes: 2

apostlion
apostlion

Reputation: 720

A somewhat naive way to handle it, but:

<% @stuff.each_with_index do |thing, i| %>
  <% if (i + 1) == @stuff.length %>
    ...
  <% else %>
    ...
  <% end %>
<% end %>

Upvotes: 2

Related Questions