Iterating through attributes with index in ruby

Question

How can i add index to iteration on attributes in ruby?

<% @child.toys.attributes.each do |attr_name, attr_value| %>

I have tried with each_with index:

<% @child.toys.attributes.each_with_index do |attr_name, attr_value| %>

But where would the index go in?

Have a look at this answer: http://stackoverflow.com/questions/2083570/possible-to-access-the-index-in-a-hash-each-loop — eugen, Oct 28 '15 at 08:54

score 3 · Answer 1 · edited May 23 '17 at 11:44

3

You could do this

<% @child.toys.attributes.each_with_index do |(attr_name, attr_value), idx| %>

edited May 23 '17 at 11:44

Community

answered Oct 28 '15 at 08:55

akbarbin

score 3 · Answer 2 · answered Oct 28 '15 at 08:56

.each_with_index appends the index variable:

%w(cat dog wombat).each_with_index {|item, index|
  hash[item] = index
}
hash   #=> {"cat"=>0, "dog"=>1, "wombat"=>2}

In your example:

<% @child.toys.attributes.each_with_index do |key,value,index| %>
    <%= key %>
    <%= value %>
    <%= index %>
<% end %>

Toys needs to be a member object (attributes won't work on a collection).

-

I also tested with just declaring "key", as follows:

<% @child.toys.attributes.each_with_index do |attr,index| %>
   <%= attr[0] %>
   <%= attr[1] %>
   <%= index %>
<% end %>

attr is returned as an array in this instance, where the key/value is used as 0 and 1 elements of the array respectively.

2 Answers2