famapp/.agents/skills/react-best-practices/upstream/rules/js-cache-property-access.md

title, impact, impactDescription, tags

title	impact	impactDescription	tags
Cache Property Access in Loops	LOW-MEDIUM	reduces lookups	javascript, loops, optimization, caching

Cache Property Access in Loops

Cache object property lookups in hot paths.

Incorrect (3 lookups × N iterations):

for (let i = 0; i < arr.length; i++) {
  process(obj.config.settings.value);
}

Correct (1 lookup total):

const value = obj.config.settings.value;
const len = arr.length;
for (let i = 0; i < len; i++) {
  process(value);
}