def edit
  @product = Product.find(params[:id])
end

def update
  # use update method
  @product = Product.find(params[:id])

  # use update_attributes to update the record
  if @product.update_attributes(product_params)
    render json: { status: :ok, message: 'Product updated ', data: @product }
  else
    render json: { status: :error, message: 'Product not available', data: @product }
  end
end

private
  def product_params
    params.require(:product).permit(:title, :price, :count)
  end