Added count function

The count function has an if/else statement checking if each element of the array is a string. Is this something you want? If so, what would you like the function to return if it fails? 
And if you did want to return null, you `return null`. That is not clever what you did. I want to return something `null`-like and `console.log() == null` so I'll return that. Ugh. When you `return f()` that reads as return the result of the function `f`. If `f` has no return it is not really a function. If `f` returned a value or `null`, that's one thing, but that's not what's happening here.