CODEWITHSUNDEEP
rubyarraysenumerable
Nathan Long
Nathan Long

Reputation: 126012

What's the fastest way in Ruby to get the first enumerable element for which a block returns true?

What's the fastest way in Ruby to get the first enumerable element for which a block returns true?

For example:

arr = [12, 88, 107, 500]
arr.select {|num| num > 100 }.first  # => 107

I'd like to do this without running through the entire array, as select will, since I only need the first match.

I know I could do an each and break on success, but I thought there was a native method for doing this; I just haven't found it in the documentation.

Upvotes: 46

Views: 18391

Answers (3)

calasyr
calasyr

Reputation: 346

I remember this using by thinking of ActiveRecord.find, which gets you the first record and ActiveRecord.select, which you use when you're getting all of them.

Not a perfect comparison but might be enough to help remember.

Upvotes: 0

Holger Just
Holger Just

Reputation: 55823

Several core ruby classes, including Array and Hash include the Enumerable module which provides many useful methods to work with these enumerations.

This module provides the find or detect methods which do exactly what you want to achieve:

arr = [12, 88, 107, 500]
arr.find { |num| num > 100 } # => 107

Both method names are synonyms to each other and do exactly the same.

Upvotes: 83

steenslag
steenslag

Reputation: 80075

arr.find{|el| el>100} #107 (or detect; it's in the Enumerable module.)

Upvotes: 3

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