Cache Property Access in Loops

web/.agents/skills/vercel-react-best-practices/rules/js-cache-property-access.md

3.172.1383 B

Cache object property lookups in hot paths.

Incorrect (3 lookups × N iterations):

typescript

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

Correct (1 lookup total):

typescript

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