React Performance: JS Perf — Early Return. Keywords: early return exit function. Platform: React/Next.js. Description: Return early when result is determined to skip processing. Do: Return immediately on first error. Don't: Process all items then check errors. Good Example: for (u of users) { if (!u.email) return { error: 'Email required' } }. Bad Example: let hasError; for (...) { if (!email) hasError=true }; if (hasError).... Severity: Low-Medium.