API Design · Middle · Question 3 of 75

How should a JSON Merge Patch request treat `null`?

PATCH /users/42
Content-Type: application/merge-patch+json

{ "nickname": null, "city": "Kyiv" }

1null sets every field to null
2null is ignored
✓Correct answer: null removes the field (nickname), present fields are updated, missing fields stay unchanged

Explanation

Merge Patch (RFC 7396) can't set a value to literal null or edit array elements; JSON Patch (RFC 6902) can, with explicit operations.

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