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You can check if a value is an array with the Array.isArray() method. You can check if a value is an object by saying typeof obj === 'object' && obj !== null. You can list the keys of an object with the Object.keys() function.
If two objects have different keys or two arrays have a different length, they cannot be equal.
You can use recursion to investigate if the values of an object or array are also deeply equal. The base case is when the values are primitives (string, number, etc), at which case the check is a trivial === check.
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Yes, variations of deep comparison and object equality problems appear in technical interviews, especially for frontend or JavaScript-heavy roles. They test understanding of recursion, object traversal, and careful handling of nested data structures.
The optimal approach uses recursive traversal to compare the structure and values of two JSON objects. Each primitive value is compared directly, while arrays and objects are checked element-by-element or key-by-key. This ensures that deeply nested structures are validated correctly.
Objects and arrays are naturally handled using recursion along with built-in structures like hash maps or key lists. Recursion allows the algorithm to traverse nested JSON levels while keeping the implementation clean and manageable.
Important edge cases include handling null values, differing key counts in objects, arrays of different lengths, and mismatched data types. Ensuring both objects have identical keys before comparing values is also critical.