# Side Effects

> Producing observable side effects in an expression, so it cannot be replaced by its value.

Record: `lex:side-effects`
Kind: anti-pattern
Layer: [Computation Core](https://banes-lab.com/records/layer/computation-core.md)
Canonical: https://banes-lab.com/ontology/lexicon#lex-side-effects

## category

- [Correctness / Determinism / Verification](https://banes-lab.com/records/lex-category/correctness-determinism-verification.md)

## referenced-by

- [Referential Transparency](https://banes-lab.com/records/arch/referential-transparency.md)