I have a problem with these puzzles that it seems like no one has pointed out. A couple of them are just intentionally misleading, specifically the ones that involve typos. For example, the solution to one of them is that it says 'defa1ut' instead of 'default' in a case statement. Ignoring the question of whether or not typos are really "puzzles", this is misleading because the syntax highlighting the author uses highlights it as if it had been spelled correctly. No actual (automatic) syntax highlighting system would ever highlight the code as it is shown on the page. It should either be presented with correct highlighting or with none at all.

For anyone who is going through these exercises, I would encourage you to copy-and-paste the code snippets into a regular text editor.