·121 words·1 min
Recently reading some posts about ruby, I found myself with this exciting method called
This method will help us when looping over some objects: Array, Hashes, and Files.
If you want to loop through a huge array, and we only want to select the first 20 elements that evaluate our criteria, this is the kind of job for our
Without the use of lazy #
arr = (1..1000).to_a selected =  arr.select do |x| selected << x if x.odd? break if selected.size > 20 end p selected
With the use of lazy method #
arr = (1..1000).to_a selected = arr.lazy.select do |x| x if x.odd? end.take(20).force p selected
The syntax is more straightforward and is better in performance.