# command–query separation

> principle that every method should either be a command that performs an action, or a query that returns data to the caller, but not both; asking a question should not change the answer

**Wikidata**: [Q3954590](https://www.wikidata.org/wiki/Q3954590)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Command–query_separation)  
**Source**: https://4ort.xyz/entity/command-query-separation