the.com/null pointer exception
the computer politely asking a question about someone who doesn't exist.
means an error thrown when code tries to use a reference that points to nothing instead of an actual object.
from traces to tony hoare's 1965 invention of the null reference, which he later called his billion dollar mistake for how much chaos it unleashed across every language that copied it.
billion dollar mistakehoare's own regretful nickname for null, coined 2009
java's versionliterally named NullPointerException, its own class
still rankedroutinely tops lists of most common runtime crashes
fix attemptskotlin, swift built entire type systems to ban it
for instance
java npe — famous enough to have its own stack overflow megathread with millions of views
c null deref — crashes segfault instead, same disease different symptom
javascript undefined — cannot read property of undefined, the web dev's nightmare
swift optionals — apple's 2014 language made you unwrap null explicitly to dodge this