This question evaluates a candidate's ability to design concise, robust test cases and translate edge-case reasoning into concrete inputs and expected outputs for array and string problems, reflecting skills in input validation, correctness assurance, and handling varied data characteristics.
For typical easy–medium array and string problems, list the most important edge cases you would test (e.g., empty input, single element, duplicates, all-equal values, already sorted or reverse order, extreme numeric ranges, Unicode or multibyte characters, and very large inputs). Show how you would turn this checklist into concrete test inputs and expected outputs quickly during an online assessment.