Curriculum
One study-notes page per domain, in interview weighting order. Read them top to bottom on a first pass, then come back to the heaviest domains. Each page shows sample questions from the bank and links to the matching drill in practice mode.
- 15% Types, Coercion & Equality 30 drill questions
Primitives, truthiness, == versus ===, ToPrimitive, NaN and -0, floating point, and the conversion puzzles interviewers open with.
- 17% Scope, Closures & Functions 34 drill questions
var versus let, hoisting and the temporal dead zone, closures over loop variables, currying, call/apply/bind, and closure-driven memory leaks.
- 15% Objects, Prototypes & Classes 30 drill questions
this binding, the prototype chain, class syntax and private fields, getters, descriptors, super, and shallow-copy traps.
- 20% Async, Promises & the Event Loop 40 drill questions
Microtasks versus tasks, promise combinators, async/await, cancellation with AbortController, and the output-order puzzles that decide screens.
- 20% TypeScript Type System 40 drill questions
Structural typing, unknown versus any, narrowing and type predicates, generics, utility and mapped types, satisfies, and conditional types with infer.
- 13% Modules, Iteration & Generators 26 drill questions
ESM versus CommonJS, live bindings, circular imports, tree shaking, the iterator protocol, generators, and async iteration.
Independent community study resource — not affiliated with or endorsed by Oracle, Microsoft or Ecma International. JavaScript is a trademark of Oracle Corporation; TypeScript is a trademark of Microsoft Corporation. All questions and study notes are original, written from MDN, the ECMAScript specification and the TypeScript handbook. Everything runs in your browser; nothing you answer is stored or transmitted.