ruby on rails - Show the last month as default in a dropdown list -

i have dropdown list months. how can show last month default? example: month september, i'd set default month august.

my view:

the dropdown list

<%      @date = date.today     @months = []     (0..11).each |m|         @months << [@date.next_month(m).strftime("%b"), @date.next_month(m)]     end %>    <div class="col-md-8">  <%= f.select :datepay, options_for_select(@months), { :required => true, :onchange => "alert()" }  %>   </div> 

currently, @months array not contain previous month.

so, include previous month in collection follows:

@date = date.today   @months = []   (-1..11).each |m| #mark here starting range -1 i.e august, 2016     @months << [@date.next_month(m).strftime("%b"),@date.next_month(m)]   end 

like have used next_month next month, prev_month can used previous month.

<%= f.select :datepay, options_for_select(@months, @date.prev_month), { :required => true, :onchange => "alert()" }  %>