What should an undefined variable evaluate to?

Question

I think most (all?) compiled languages evaluate to a compilation error.As for NodeJS, I thought it would evaluate to `undefined`, but it seems to consistently throw a `ReferenceError` for version 20.What's the result for other languages?

Doctor-R · Accepted Answer

Ages ago, the Digital Equipment VAX had a hardware hack where a null pointer (value is 0) would return a 0 when de-referenced. Which is the null character, the end of a string. So most of the time operations moving characters would terminate correctly. Obviously not portable to other computers.In the IEEE 754 floating point definition, there are specific values for errors: mathematically undefined, division by zero, overflow, underflow, and inexact. These MUST be implemented in hardware to meet the specification.