Is there an equivalent of Array#find_index for the last index in ruby?

Question

Array#find_index allows you to find the index of the first item that either

• is equal to an object, or
• makes a block passed to it evaluate to true

Array#rindex can allow you to find the index of the last item that is equal to an object, but is there anything that allows you to find the index of the last item that makes a block passed to it return true?

Otherwise, should I do something like

last_index = array.length - 1 - array.reverse.find_index{|item| item.is_wanted?}

Answer 1

In Ruby 1.9.2 Array#rindex accepts block: http://apidock.com/ruby/Array/rindex

Answer 2

Or you could do something like

last_index = array.map {|i| i.is_wanted? }.rindex(true)

which is a bit prettier

Answer 3

Such a shame it comes until 1.9.2. In the meantime, if you don't want to reverse your array, but rather enumerate the search in reverse, you can do

last_index = array.length - 1 - array.rindex.find_index{|item| item.is_wanted? } (1.8.7 and up)