Question: Say I have a hash like: 

```
h = { '0' => 'foo', 'bar' => 'baz' => '2' => 'yada'  }

```

How would I go about determining if this hash has any numeric keys in it and pulling out the values of those keys?

Answer: 
try this:

```
h.select {|key| [*0..9].map(&:to_s).include? key }

```

remember that I didn't pulled out the value for you, it just returns a selection of your hash with the desired criteria. Pulling the values out this hash like you're used to.
Or for a possibly slightly more readable but longer solution, try:

```

    class String
      def is_i?
        # Returns false if the character is not an integer
        each_char {|c| return false unless /[\d.-]/ =~ c}
        # If we got here, it must be an integer
        true
      end
    end
    h = {"42"=>"mary", "foo"=>"had a", "0"=>"little", "-3"=>"integer"}
    result = []
    h.each {|k, v| result << v if k.is_i?} 

```