how to group objects in an array Ruby

I have an array of users who are managers.

However there are repeated Users.

I would like to group them so that there is only one instance of each User in the array.

What would be the best 开发者_开发知识库way to go about this?

@managers.sort_by{|obj| obj.id} # Just sorted the data but did not eliminate duplicats

@managers.group_by{|u|u.name}    # just created a bunch of arrays for each name

Use the uniq method, which returns a new array with duplicates removed.

@managers.uniq

If by duplicate you mean the same object ID, then you can do the following:

@managers.uniq.group_by(&:name)

Filtering the array feels like fixing symptoms. Why does the array contain rubbish in the first place?

I would suggest adding a manager? method to your User model that returns true if the user is a manager. Then you could to something like

@managers = User.select &:manager?

and get an array that only contains managers.

you can also do

Manager.select('DISTINCT user_id')

to get a clean array in the first place, whith better performance.