Pretty standard once you see it a few times.
Start by clarifying the requirements: discuss handling of arrays, null, undefined, and empty objects. Then, present a recursive solution that builds the path as it traverses the object, and finally analyze time and space complexity and potential trade-offs with iterative approaches.
Pro tip: Mention that you would use a delimiter that is unlikely to appear in keys (e.g., a dot) and discuss how to handle collisions if keys already contain dots. Also, consider using an iterative stack-based approach to avoid stack overflow for deeply nested objects.
Ask about handling arrays, null, undefined, empty objects, and keys containing dots. Confirm the expected output format and whether the original object should be mutated.
Decide between recursive and iterative (stack-based) solutions. Discuss the trade-offs: recursion is simpler but may cause stack overflow; iteration is more complex but safer for deep nesting.
Write clean code that traverses the object, building the path for each key. For recursion, pass the current path and result object; for iteration, use a stack of [object, path] pairs.
Walk through test cases: simple nested object, arrays, empty objects, null values, and keys with dots. Verify that the output matches expectations.
State that time complexity is O(n) where n is the total number of keys, and space complexity is O(n) for the output. Discuss potential improvements or alternative approaches.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.
This one tripped me up more than I'd like to admit.
Start by clarifying requirements and edge cases, then outline the algorithm: iterate over inputs, wrap each in Promise.resolve, track completion count, and resolve when all are done. Write clean code with proper error handling and discuss trade-offs like concurrency and ordering.
Pro tip: Mention that native Promise.all uses a counter and resolves only when all promises settle, and that it rejects immediately on first rejection but other promises continue executing. Also note that non-promise values are resolved as-is.
Ask about input types (iterable, promises, plain values), handling of empty iterable, and whether rejection should cancel other promises. Confirm that order must be preserved.
Explain that you'll convert the iterable to an array, create a results array, and use a counter to track resolved promises. For each input, wrap it in Promise.resolve and attach then/catch handlers.
Write code that returns a new Promise. Inside, handle empty input by resolving immediately. For each item, on fulfillment store the value at the correct index and increment the counter; when counter equals length, resolve with results. On rejection, reject the outer promise.
Walk through examples: all resolve, one rejects, mixed plain values and promises, empty array, and non-array iterables. Mention that other promises continue but their results are ignored after rejection.
Talk about concurrency (all start immediately), memory usage (storing all results), and potential improvements like limiting concurrency or using async/await for readability.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.