Building a hash in a conditional way

Question

I am using Ruby on Rails 3.0.10 and I would like to build an hash key\\value pairs in a conditional way. That is, I would like to add a key and its related value if a condition

Answer 1

IF you build hash from some kind of Enumerable data, you can use inject, for example:

raw_data.inject({}){ |a,e| a[e.name] = e.value if expr; a }