Rails adding nested params

class ClassroomsController < ApplicationController
  def update
    @classroom = Classroom.find(params[:id])
    if @classroom.update(classroom_params)
      program_ids = classroom_program_params[:program_ids].delete_if {|program| program == ""}
      @programs = program_ids.map {|id| Program.find(id)}
      @classroom.update(programs: @programs)
      redirect_to users_path, :notice => "#{@classroom.name} updated"
    else
      flash[:notice] = "Classrooms must have a name"
      @programs = Program.all
      render :edit
    end
  end
  
private

  def classroom_program_params
     params.require(:classroom).permit({:program_ids => []})
  end

  def classroom_params
    params.require(:classroom).permit(:name, :location, :map_url, :image_url, :description, :longitude, :latitude, :google_address, :phone)
  end
end