Sort an array according to the elements of another array

Question

I have an array of ids

a1 = [1, 2, 3, 4, 5]  

and I have another array of objects with ids in random order

a2 = [(obj_w         


        

Answer 1

Inspired by Eric Woodruff's Answer, I came up with the following vanilla Ruby solution:

a2.group_by(&:object_id).values_at(*a1).flatten(1)

Method documentation:

• Enumerable#group_by
• Array#values_at
• Array#flatten