Post List of Values to model params - ruby

Question

I am creating instructors page which have multiple course ids to be passed to the model parameter list.
The following is my code for whitelist params
def instructor_params
params.require(:instructor).permit(:LastName, :FirstMidName, :HireDate, {:courses_ids => []})
end
My create page is like below
<%= form_for #instructor, :html => { :class => "form-horizontal instructor" } do |f| %>
<% if #instructor.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(#instructor.errors.count, "error") %> prohibited this instructor from being saved:</h2>
<ul>
<% #instructor.errors.full_messages.each do |message| %>
<li><%= message %></li>
<% end %>
</ul>
</div>
<% end %>
<div class="form-group">
<%= f.label :LastName, :class => 'control-label col-md-2' %>
<div class="col-md-10">
<%= f.text_field :LastName, :class => 'form-control' %>
<%= error_span(#instructor[:LastName]) %>
</div>
</div>
<div class="form-group">
<%= f.label :FirstMidName, :class => 'control-label col-md-2' %>
<div class="col-md-10">
<%= f.text_field :FirstMidName, :class => 'form-control' %>
<%= error_span(#instructor[:FirstMidName]) %>
</div>
</div>
<div class="form-group">
<%= f.label :HireDate, :class => 'control-label col-md-2' %>
<div class="col-md-10">
<%= f.text_field :HireDate, :class => 'form-control' %>
<%= error_span(#instructor[:HireDate]) %>
</div>
</div>
<div class="form-group">
<%= f.label text="Courses", :class => 'control-label col-md-2' %>
<div class="col-md-10">
<table cellpadding="5">
<tr>
<td>
<input type="checkbox" name="course_ids" value="Course1">Course1
<input type="checkbox" name="course_ids" value="Course2">Course2
<input type="checkbox" name="course_ids" value="Course3">Course3
</td>
</tr>
</table>
</div>
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<%= f.submit nil, :class => 'btn btn-primary' %>
<%= link_to t('.cancel', :default => t("helpers.links.cancel")),
instructors_path, :class => 'btn btn-default' %>
</div>
</div>
<% end %>
But if select multiple check-boxes params not passing as arrays. ?It took only the last one and showing not permitted. Please guide me. I don't have any attribute named course_ids in Instructor model.

Answer 1

To receive an array of values, you need to change the name of your checkboxes to be course_ids[]
In your permitted params, {:courses_ids => []} can be written simply as course_ids: [] (also notice the typo you had with the plural 'courses').