Ruby Array find first object

Question

Am I missing something in the Array documentation   I have an array which contains up to one object satisfying a certain criterion   I d like to efficiently find that object   The best idea I have from the docs is this   candidates   my array select    e  e satisfies condition    found it   candidates first if  candidates empty    But I am unsatisfied for two reasons    That select made me traverse the whole array  even though we could have bailed after the first hit  I needed a line of code  with a condition  to flatten the candidates      Both operations are wasteful with foreknowledge that there s 0 or 1 satisfying objects   What I d like is something like   array find first block    which returns nil or the first object for which the block evaluates to true  ending the traversal at that object   Must I write this myself   All those other great methods in Array make me think it s there and I m just not seeing it

User · Answer

Do you need the object itself or do you just need to know if there is an object that satisfies. If the former then yes: use find:

found_object = my_array.find { |e| e.satisfies_condition? }

otherwise you can use any?

found_it = my_array.any?  { |e| e.satisfies_condition? }

The latter will bail with "true" when it finds one that satisfies the condition. The former will do the same, but return the object.

User · Answer

Either I don t understand your question  or Enumerable find is the thing you were looking for

User · Answer

use array detect method if you wanted to return first value where block returns true   1 2 3 11 34  detect  amp  even      gt  2  OR   1 2 3 11 34  detect  i  i even      gt  2   If you wanted to return all values where block returns true then use select   1 2 3 11 34  select  amp  even       gt   2  34

User · Answer

Guess you just missed the find method in the docs   my array find   e  e satisfies condition

[ruby] Ruby Array find_first object?

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