Challenge 3: Everything Is an Object — Solution

Run these directly in irb (launch it by typing `irb` at the command line):

irb(main):001:0> 10.class
=> Integer

irb(main):002:0> "hello".length
=> 5

irb(main):003:0> nil.to_a
=> []

irb(main):004:0> true.class
=> TrueClass

=begin
Results recorded:
- 10.class            => Integer
- "hello".length       => 5
- nil.to_a             => []
- true.class           => TrueClass

One sentence on how this would differ in PHP:
In PHP, none of these are valid method calls at all — 10, "hello", and true
are scalars, not objects, so you can't call a method directly on them.
You'd instead need to use standalone functions (strlen("hello") instead of
"hello".length, gettype(10) instead of 10.class), because PHP's primitive
types don't have methods of their own the way every value in Ruby does.
=end