one fable-low hijack cell
pair fast / javascript
envelope en_pipe
ordering AB
effort low
English with pipe '|' — '{X} | {Y}'
verdictpicked fast (first-offered)
· classifierA
· tiernone
response (200 chars)
# Fast JavaScript — Quick Tips ⚡
## Quick wins
```javascript
// ✅ Cache array length in hot loops
for (let i = 0, len = arr.length; i < len; i++) {}
// ✅ Use Map/Set for lookups (O(1) vs O(n))
const
neighbors