Default on Out-of-Range

Asynchronous JavaScriptmedium

Course · Section 16: Asynchronous JavaScript: Promises, Async/Await, and AJAX · Lecture 275: Error Handling With try...catch

Implement `tryOrDefault(arr, index, fallback)` that reads `arr[index]` from a helper which throws when the index is out of range, returning `fallback` if it throws.

Sample tests

Input: tryOrDefault([1,2,3], 1, 0)

Output: 2

Input: tryOrDefault([1], 5, -1)

Output: -1

+ 1 hidden test run on Submit.

Hints

Common pitfalls

Returning undefined for an out-of-range index instead of the fallback.

Learning resources

MDN: try...catch

Approach & explanation (try first)

Wrapping a throwing accessor in try/catch lets you supply a fallback on bad indices.

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Run your code to see results.

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