Function isKeyOf

isKeyOf<T extends object, K extends string>(obj: T, key: string): key is K
Tests whether or not a key string is a key of the given object type T.
Type Parameters
- T extends object
- K extends string
Parameters
- obj: T
  The target object to check the key in.
- key: string
  The string to test as a key of the target object.
Returns key is K
- Defined in narrowing/is.ts:215