searching an array using another array of values in ruby

So I have an array which shows which levels are allowed to do things.

allowed = ["user", "admin"]

There's another array that shows which groups a user belongs to.

groups = ["user", "crazy"]

What's th开发者_如何学Pythone best way to search the allowed array for ANY of the groups a user belongs to? I know it's easy but I'm drawing a real blank here...

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Just &:

allowed & groups

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Convert to a set and do an intersection.

require 'set'

allowed = ["user", "admin"]
has = ["user", "print"]
puts(allowed.to_set.intersection(has.to_set)) # prints #<Set: {"user"}>