FrontendHaltTypeScript·Beginner·Conceptual·1 min read
What does NonNullable<T> do?
Short interview answer
It removes null and undefined from a type, which is useful when narrowing a value that's known through other logic to always be present, without repeating a manual conditional type.
Key takeaway
Explain the underlying mental model clearly, then support it with a concrete example and its trade-offs.