This is interesting, but I don't think it is a good way to learn javascript.

The problem for me is that many of the examples seem to intend to be tricks, and I'm not sure all of the answers are correct, given this context of trickery.

For example. In self invoking functions, the answer to the final question is apparently to add a bash function as "!function". I've never seen this used before, and personally, I don't think it makes sense from a readability standpoint. why would "not function" be expected to cause a function to run? I'm not suggesting it doesn't, I'm just suggesting it maybe isn't good practice as many other programmers may not be familiar with the syntax.

Then, in the Floats section, question one asks "What returns calculateAmountOfStockOptions ?". To me, "What returns" is asking, which function or method is returning calculateAmountofStockOptions, but apparently the correct answer is the value.

The second question of Floats asks "What is the value of calculateChange ?", and though it asks to input the number value, these questions don't make sense. calculateChange is a function, therefore it's value is an object, not a number.

I think this is too confusing in it's current state to be a good learning too.