Some ruby array quirks you may not know about

Array discards the splatted nil:

irb > [1,2,3,*nil]
# => [1, 2, 3]

This knowledge comes in handy when you are splatting a variable which is intended to be an array, but returns nil as shown below:

irb > foo = nil
=> nil
irb > [1,2,3,*foo]
=> [1, 2, 3]

Array treats empty expressions as nil:

irb(main):005:0> [1,2,3,()]
=> [1, 2, 3, nil]

I honestly, don’t know where this can be useful. But it’s good to know this stuff right?

Fun Fact:

Empty expressions return nil, regardless of the context of arrays:

irb > ()
=> nil