Is it a good idea to use IEEE754 floating point NaN for values which are not set?

Question

Is it a good idea to use IEEE754 floating point NaN (not-a-number) for values which are undefined for non-mathematical reasons?

In our case they are not yet set beca

Answer 1

I have used NaNs in similar situations just because of that: the usual default initialization value 0 is also a valid value. NaNs work fine so far.

It's a good question, by the way, why the default initialization value is usually (for instance, in Java primitive types) 0 and not NaN. Couldn't it as well be 42 or whatever? I wonder what's the rationale of zeros.