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Ask HN: What should an undefined variable evaluate to?

1 pointsby carlosneves8 months ago
I think most (all?) compiled languages evaluate to a compilation error.<p>As for NodeJS, I thought it would evaluate to `undefined`, but it seems to consistently throw a `ReferenceError` for version 20.<p>What&#x27;s the result for other languages?

1 comment

Doctor-R8 months ago
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.<p>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.
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