Question

Is it bad to check if an array is not empty by using any? method?

a = [1,2,3]

a.any?
=> true

a.clear

a.any?
=> false

Or is it better to use unless a.empty? ?

Answer 1

any? isn’t the same as not empty? in some cases.

>> [nil, 1].any?
=> true
>> [nil, nil].any?
=> false

From the documentation:

If the block is not given, Ruby adds
an implicit block of {|obj| obj} (that
is any? will return true if at least
one of the collection members is not
false or nil).