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TypeScript Essentials

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Types & Interfaces

TypeScript adds static typing to JavaScript. Learn primitive types, object shapes with interfaces, and when to use type vs interface. This outline is in progress — expect a short read until full lessons ship.

Check your understanding

  • When might you prefer interface over type for an object shape?Show answer

    Answer

    Interfaces declare object shapes and can be extended/merged; type aliases are better for unions and mapped types. Either works for simple objects.
  • What problem does TypeScript catch that plain JS misses until runtime?Show answer

    Answer

    Static type errors — calling a function with the wrong argument shape, accessing missing properties, and similar mistakes.

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