Rails Noob, Math or Array Issue?

rubyonrails-talk
1

Let's say that below is the math for figuring out a unit in a popular diet program:

    @fiber = Array.new(@food.fiber, 4)     @points = (@food.calories / 50) + (@food.fat / 12) - (@fiber.min / 5)

And that for personal use, I'm creating a system to keep track of these units on a daily basis and I'm simply rendering @points in the following manner in my view:

   <p><b>Points:</b> <%= @points %></p>

But when @points equals 0, I get the nasty message:

NoMethodError in FoodsController#show

You have a nil object when you didn't expect it! The error occurred while evaluating nil./

What would one do to make it OK to have a 0 instead of causing it to evaluate nil?

2

I goofed up...when the minimum of @fiber = 0, I get the nasty message...not when @points = 0. I apologize.

3

Finally figured it out on my own with some modifications...

Controller:   def show     @food = Food.find(params[:id])     @fiber = Array.new(@food.fiber.to_f, 4)     @points = (@food.calories.to_f / 50) + (@food.fat.to_f / 12) - ((@fiber.min.to_f) / 5)   end

View: <p><b>Points:</b> <%= @points.round %></p>

Seems to produce the results I want...any better way would be welcome.

4

What I need is something that returns the minimum of food.fiber or 4, whichever is lower. I appreciate your help--I'm just a programming idiot to begin with and even moreso at Ruby/Rails.