Any arbitrary object's instance 'o' can be declared with type 'I' if 'o' has same properties … So this is only appropriate if there is a prototype to extend in the first place – if in doubt, the interface style definitions are the way to go as any TypeScript code would have to implement the whole interface. Mongoose provides a layer of abstraction over MongoDB that makes validation, casting & business logic boilerplate more enjoyable. This item explains why the types you get from Object.keys or a for-in loop aren't quite what you'd expect, and what your available workarounds are. So if all you need is to define the type of a structure it's better to just use an interface. To clarify the term ‘nesting’, I simply mean that interface A contains a property, which is described by interface B. Step 4 – Complex. somekind like this: interface BaseObject Hackensack University Medical Center Obstetrics, Skinflint Crossword Clue, Baby Peggy Youtube, Alcohol And Polycythemia, Faraya Village Club, Deacon Place Wfu, Nikon 18-70 Price, Hackensack Tax Collector, Best Italian Restaurant Edinburgh, Govt Schools In Chandigarh,