Files
5chan/.claude/skills/vercel-react-best-practices/rules/js-set-map-lookups.md
T
Tommaso CasaburiandClaude Opus 4.6 189d1c2165 add .claude config folder with Claude-equivalent agent and hook settings
Mirrors .cursor and .codex structure with Claude model assignments:
- haiku for lighter tasks (translator, browser-check, profiler)
- sonnet for standard tasks (code-quality, plan-implementer, etc.)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
2026-03-29 16:35:21 +07:00

532 B

title, impact, impactDescription, tags
title impact impactDescription tags
Use Set/Map for O(1) Lookups LOW-MEDIUM O(n) to O(1) javascript, set, map, data-structures, performance

Use Set/Map for O(1) Lookups

Convert arrays to Set/Map for repeated membership checks.

Incorrect (O(n) per check):

const allowedIds = ['a', 'b', 'c', ...]
items.filter(item => allowedIds.includes(item.id))

Correct (O(1) per check):

const allowedIds = new Set(['a', 'b', 'c', ...])
items.filter(item => allowedIds.has(item.id))