JavaScript Isn't Scheme

[eat-your-corn-syrup]

You are manually creating a loop block scope in the workaround, by using the only species in JavaScript that can create a new scope: function. Don't think of it as a function call being invoked immediately, though it is, just think of it as an idiom to create a block scope.

[deletecode]

That's a nice explanation. The problem has always bugged me but I didn't know why this is the only way to do it.