asios/.agent/skills/vercel-react-best-practices/rules/js-cache-property-access.md

---

title: Cache Property Access in Loops impact: LOW-MEDIUM impactDescription: reduces lookups

tags: 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)
}