From: "Peña, Botp" <botp@...>
Date: 2007-10-22T12:21:31+09:00
Subject: Re: What's the ruby way of grouping elements of an array?

On Behalf Of Sam Kong:
# people.group_by do |person|
#   person.age
# end
# The above method should return an array of arrays 
# grouped by age. What's the ruby way for this case?
# I think I can implement it but I am sure that a good 
# way already exists.

as you've said (and as others have offered), you'll have to implement it or use another lib/gem.

if you can wait for ruby2 (or use 1.9), the group_by and symbol's to_proc is a good combi. eg,

> people.group_by{|person| person.age}
...
or

> people.group_by(& :age)
...
> RUBY_VERSION
=> "1.9.0"

btw, group_by returns hash of arrays

kind regards -botp