Question

I am using a ruby iterator on a view in a rails app like so:

<% ([e-mail]).each_with_index do |element, index| %>
  ...
<% end %>

I thought the addition of the 1.. instead of just saying:
@document.data

would get the trick of having the index above start at 1. But alas, the above code index is still 0 to data.length (-1 effectively). So what am I doing wrong, i need the index to equal 1-data.length…no clue how to set up the iterator to do this.

Answer 1

I think maybe you misunderstand each_with_index.

each will iterate over elements in an array

[:a, :b, :c].each do |object|
  puts object
end

which outputs;

:a
:b
:c

each_with_index iterates over the elements, and also passes in the index (starting from zero)

[:a, :b, :c].each_with_index do |object, index|
  puts "#{object} at index #{index}"
end

which outputs

:a at index 0
:b at index 1
:c at index 2

if you want it 1-indexed then just add 1.

[:a, :b, :c].each_with_index do |object, index|
  indexplusone = index + 1
  puts "#{object} at index #{indexplusone}"
end

which outputs

:a at index 1
:b at index 2
:c at index 3

---

if you want to iterate over a subset of an array, then just choose the subset, then iterate over it

without_first_element = array[1..-1]

without_first_element.each do |object|
  ...
end