Strong parameters with array

controller

  def create
   p "++++++++#{permitted_params.user.inspect}"
   p "++++++++#{permitted_params.user['role_ids'].inspect}"
   @user = User.new(permitted_params.user)
   if @user.save
    flash[:notice] = 'User was successfully created.'
    redirect_to edit_admin_user_url(@user)
  else
    render :action => 'new'
  end
end

permitted_params.rb

#this is a permitted_params file
  def user
      params.require(:user).permit(:first_name, :last_name, :email, :language,
                  		   :access_level_id, :current_group_id,
                  		   :first_login, :signed_license,
                  		   :password, :password_confirmation,
                                   :read_stories_at,			
                                   :currency_id,
                                   user_groups_attributes: [:group_id,:id, '_destroy'],
                                   user_roles_attributes: [:role_id,:id, '_destroy'],
                                   :role_ids => [])

user.rb

class User < ActiveRecord::Base
  has_many :user_roles, :dependent => :destroy
  accepts_nested_attributes_for :user_roles, :allow_destroy => true
  has_many :roles, :through => :user_roles
end

view

   
      <li>
        <%= hidden_field_tag "user[role_ids][]", nil %>
        <%= check_box_tag 'user[role_ids][]', role.id, user.blank? ? nil : user.roles.include?(role) ,id: dom_id(role)%>
        <%=  label_tag dom_id(role), "#{role.group.name}: #{role.name}" -%>
      </li>
 

good