Question

With my array of hashes:

data = [{:bool => true, :val => 5}, {:bool => false, :val => 9}, {:bool => true, :val => 1}]

I would like to iterate through the data and retrieve an array of values only. I can do:

data.map{|x| x[:val] if x[:bool]}

which returns:

[5, nil, 1]

But this method requires an additional .compact call to get rid of the nil values.

Is there a better way of achieving this?

Answer 1

Use chaining instead to first select only those where :bool is true, then map the results to :val:

data.select { |h| h[:bool] }.map { |h| h[:val] }  #=> [5, 1]