any? Method

@numbers = [1, 0, 3, 2, 5, 4, 7, 6, 9, 8]

# are any numbers even?
@numbers.any?(&:even?)    #=> true

# are any numbers negative?
@numbers.any?{|number| number < 0}    #=> false

# if list is empty, is anything true?
[].any?(&:even?)    #=> false

Unilke the all? method, calling any? on an empty collection will return false. This is because the method is looking for at least one true value to be returned, and it receives none.

# do any pets have three legs?
@inventory.any?{|pet| pet.legs == 3}    #=> false

# are any pets sold out?
@inventory.any?(&:sold_out?)    #=> true

# do any pets have a quantity of just one? 
@inventory.any?{|pet| pet.quantity == 1}    #=> true

Just like with our simple number list, any? is looking for at least one true result after executing the given block on every item in the collection.

# do any pokey things have at least 5 letters?
@pokey_things.seek(0) # starting at the beginning of the file
@pokey_things.any?{|line| line.size >= 5}    #=> true

# are pillows on the list of pokey things?
@pokey_things.seek(0) # starting at the beginning of the file
@pokey_things.any?{|line| line.include?('pillow')}    #=> false

We do have a couple pokey things with at least five letters, so our first test passes. The word "pillow", however, doesn't appear in any part of our list, not even as part of a larger phrase. This makes sense - even if you're building a complicated poking device, pillows are never going to add value to the equation.