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

I use merge and the ternary operator for that situation,

hash = {
  :key1 => value1,
  :key3 => value3,
  ...
}.merge(condition ? {:key2 => value2} : {})