[weaksauce]

there are many ways to lookup if something is defined or not

    instance_variable_defined?

    defined?

are two common ones

but if you are using something before defining it you are going to crash so that's definitely one way of distinguishing it.

using fetch is another way to provide a default value to something that may have a nil value as a meaningful value.

[CoffeeOnWrite]

Thanks for correcting me (sincerely)

> but if you are using something before defining it you are going to crash so that's definitely one way of distinguishing it.

Would you clarify? Like that was my point, casually using something where `nil` is a possible assigned value, or maybe the variable hasn't been defined, makes possible the (sadly common) category of bugs where the program does not crash, but proceeds as though the variable was assigned `nil`, but actually the variable was never defined.

In contrast to local variables where the program will crash if you reference the variable but it hasn't been defined.

My comment meant "bare instance variables in Ruby are not great [and we might not want to recommend them as a solution to people complaining about Ruby/Rails quirks]". Do you disagree and actually love the behavior of Ruby instance variables? Or are you simply technically correcting me? (which, again, I appreciate)

[weaksauce]

> Do you disagree and actually love the behavior of Ruby instance variables

yeah I wouldn't say i love it and i'm not sure why they did that but i imagine they had a reason for it originally. i would say it should have crashed instead of return nil as a default. they did tend to try to make the programmer happier and maybe they did it to that end but i don't see a large upside to it... not too much we can do about not using instance variables though... at the end of the day you just have to be a little more careful.

tests are a pretty good thing to have though and can catch this kind of error.