Diff two objects in TypeScript
TypeScript interview exercise on Practical, difficulty 2 of 3. Solve it in the editor beside a worked example; the tests run the moment you do.
Write diffKeys(before, after) that returns { added, removed, changed } — arrays of key names, each sorted alphabetically. changed means present in both with a different (===) value.
Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Progress is saved in your browser, and in your account if you sign in.