| # | title | topic | type | difficulty |
|---|---|---|---|---|
| 1 | Array.prototype.at is generic | Arrays | Multiple choice | Hard |
| 2 | Pair sum detection with .some() only | Arrays | Coding | Hard |
| 3 | Matrix validation with .every() | Arrays | Coding | Hard |
| 4 | Function composition with reduceRight | Arrays | Coding | Hard |
| 5 | Sparse arrays and holes |
| Arrays |
| Multiple choice |
| Hard |
| 6 | Rebuild Array.prototype.reduce — holes and all | Arrays | Coding | Hard |
| 7 | Rebuild Array.prototype.with (ES2023) | Arrays | Coding | Hard |