CODEWITHSUNDEEP
ruby-on-railsruby
Jake
Jake

Reputation: 1370

In Rails how to exclude do an index position on an each_slice?

I have an array of posts with the following numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10].

In my ERB I have the following:

<% @post.each_slice(2) do |post, b| %>
 <% if post.number != 1 %>
  <%= post.number %>
  <%= image_tag post.post_image %>

  <%= b.number %>
  <%= image_tag b.post_image %>
 <% end %>
<% end %>

Basically I want rows of the following:

[2, 3]
[4, 5]
[6, 7]
[8, 9]
[10]

When I use the code above I end up with:

[3, 4]
[5, 6]
[7, 8]
[9, 10]

I kind of understand why. I'm basically saying slice into two and then I'm saying "well get rid of 1" so that gets rid of 1 and 2. What's the simplest way to say each_slice starting at index 1?

Upvotes: 0

Views: 316

Answers (2)

Marek Lipka
Marek Lipka

Reputation: 51151

You can easily get rid of the first element of an array to iterate over the rest (in a way you want), using [] operator:

<% @post[1..-1].each_slice(2) do |post, b| %>
  # ...
<% end %>

also, I guess you should check if the second post exists (in case your array is even, like in your example), like this:

<% if b %>
  <%= b.number %>
  <%= image_tag b.post_image %>
<% end %>

Upvotes: 2

Rahul Sharma
Rahul Sharma

Reputation: 1431

Do something like this 

<% @post.drop(1).each_slice(2) do |post, b| %>
  # ...
<% end %>

This will produce output like this.

[2, 3]
[4, 5]
[6, 7]
[8, 9]
[10]

Upvotes: 3

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