John Carmack on mutable variables

There are languages nobody uses, and languages people complain about. Computing is about change, otherwise there is nothing to compute. The mere fact that its called a “variable” makes it obvious that its supposed to change.

This is a viewpoint commonly held by students who were exposed to imperative programming before having any class in maths. However it shouldn't survive long after that.

Bjarne's excuse is very silly, it's like the Laffer curve but for programming language defects. It pins one edge case nobody cares about, then tries to imply that's proof for a claim no sane person could agree with and for which there is no evidence. Bjarne says languages with no users attract no complaints regardless of how terrible they are (nobody was arguing that they do), therefore implies Bjarne, the fact that people complain about my language just means it is popular. Bzzt, wrong. They're complaining because it's so riddled with problems.

Variables are distinct from constants. It's a problem that C and C++ use the keyword "const" to signify immutability instead, indeed as a result C++ needed three more keywords "constexpr", "constinit" and "consteval" to try to grapple with the problem.