Type Alias UnionKeys<U>

UnionKeys: U extends any ? keyof U : never

Extract all keys from a union of object types.

Type Parameters

U
Union of object types

Remarks

Produces the union of keys that appear in at least one member of the union.

Example

type U = { a: string } | { b: number };
type K = UnionKeys< U >;  // 'a' | 'b'