Is there a built-in binary-search In Ruby?

Question

I am looking for a built-in Ruby method that has the same functionality as index but uses a binary search algorithm, and thus requires a pre-sorted array.

Answer 1

I use bsearch. This is how it works:

array = ['one', 'two', 'three', 'four', 'five']

search = array.sort.bsearch { |value| 'four' <=> value }

Note: binary search needs a sorted array; this adds a li'l overhead but it's fine, compared to the speed of the search.

search will return the value four of the array, else nil if it doesn't find the value.