Those last examples happen when you have variables containing those values. Without strict type checking, it gets really hard to know in all situations (especia

Those last examples happen when you have variables containing those values. Without strict type checking, it gets really hard to know in all situations (especially when you're pulling values from a service) what you will have in there. And if a service changes, you won't have a lot of warning in your client code. So yes, these kinds of errors are very common.