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

Using NaN as a default value is reasonable.

Note that some expressions, such as (0.0 / 0.0), return NaN.