re: Poll: Do You Know What "Idempotent" Means? VIEW POST


Thank you for introducing the arcane term, that people should be aware of, Thorsten.

I've only heard "of" the term, Idempotent and been using functions/methods without knowing what it was 😅

1️⃣ First example is SQL server not allowing User-defined functions (UDFs) to call stored procedures (sprocs) as sprocs can have side effects (writing/update database) while UDFs do not allow it (as it needs to be pure).

2️⃣ Second example is in React's setState, where it requires to pass a pure function (meaning having no side-effects) to return a new state object instance (for reconciliation optimization).

I've only realized that after reading your linked Wikipedia article under Computer science meaning section in which it reads,

in functional programming, a pure function is idempotent if it is idempotent in the mathematical sense given in the definition.

code of conduct - report abuse