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Js Cache Property Access

Source: .agents/references/coding-standard/vercel-react-best-practices/rules/js-cache-property-access.md

Metadata​

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

Content​

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)
}