I love how the tone of the tutorial is as if it was written for a twelve year old. "You've heard of types, right? Pretty cool, huh? Well, check this out! We can concatenate strings, and, wait for it NUMBERS!!1! And, best of all, the _type_ checker will make sense of it! Who'd have thought?!?"
And this is a direct quote: Surely it's not the "Hello, World!" that's written in the following "statement"? Indeed, it is, even though it seems to appear after the place where we use it!
Wow, really? A compiler that's free to execute statements in any order as long as the meaning stays the same? What a novel idea!