Question

I’d like to debug a variable @num in my Rails controller, so I’m evaluating

<%= @num %> 

in my Rails view. However, I cannot distinguish between @num being '', ' ', and ' ' (and other different types of whitespace) when it’s printed in the HTML. Is there any way to print it out clearly?

Answer 1

If you want to be really sure:

<%= @num.inspect %>

When @num = ' ' this should render:

" "

#inspect is great when you want to a representation of some object as a string.

If this is a complex object or large array or deep hash, I often prefer #to_yaml for inspection which lays it out in a somewhat readable format.

# controller
@foo = {:a => [:bar, :baz], :b => 123, :c => 'omg'}

# view
<pre><%= @foo.to_yaml %></pre>

# visible output
--- 
:b: 123
:c: omg
:a: 
- :bar
- :baz