API Design · Middle · Question 64 of 75

Why should API responses avoid exposing nulls for fields that are 'not applicable' vs 'unknown' without documentation?

✓Correct answer: Clients can't tell missing, empty and null apart unless the contract defines what each means
2JSON doesn't allow null
3Null fields break HTTP

Explanation

Decide whether absent and null differ, and document it, especially for PATCH semantics.

Further reading

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