Safe Array Indexing
Safe Array Indexing
Array indexing returns undefined when a position does not exist. That can be fine inside quick scripts, but application code often needs a clearer result when an index comes from a URL, form field, or saved setting.
A small helper can turn a raw index read into an explicit contract. The caller gets the array item for valid positions and a deliberate fallback for positions outside the list.
Your task: Complete itemAt so it returns the item at the requested index when that index is valid. Return null for negative indexes, indexes past the end, and empty arrays.
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Safe Array Indexing
Array indexing returns undefined when a position does not exist. That can be fine inside quick scripts, but application code often needs a clearer result when an index comes from a URL, form field, or saved setting.
A small helper can turn a raw index read into an explicit contract. The caller gets the array item for valid positions and a deliberate fallback for positions outside the list.
Your task: Complete itemAt so it returns the item at the requested index when that index is valid. Return null for negative indexes, indexes past the end, and empty arrays.