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Intermediate30 questions60 minutes

TypeScript Intermediate Quiz

Explore generics, enums, and more advanced type manipulations.

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Sample questions from this quiz

A preview of the style and depth. Try each one, then reveal the answer — or skip straight to the timed quiz.

1. What is a generic in TypeScript?

function identity<T>(arg: T): T { return arg; }
  • A reusable component that can work with a variety of types.
  • A base class for other classes.
  • A special type of interface.
  • A way to generate code.
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Answer: A reusable component that can work with a variety of types.. Generics allow you to create reusable components (functions, classes, interfaces) that can work over a variety of types rather than a single one.

2. How do you define a numeric enum?

enum Direction { Up, Down, Left, Right }
  • enum Direction { Up, Down, Left, Right }
  • type Direction = 'Up' | 'Down';
  • const Direction = ['Up', 'Down'];
  • interface Direction { Up, Down }
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Answer: enum Direction { Up, Down, Left, Right }. By default, enums are number-based, with the first member being 0 and auto-incrementing from there.

3. What is the value of `Direction.Left` in this enum?

enum Direction { Up = 1, Down, Left, Right }
  • 1
  • 3
  • 0
  • 2
Show answer

Answer: 3. When one member is initialized (Up = 1), subsequent members auto-increment. So, Down is 2, and Left is 3.

Frequently asked questions

How many questions are in this TypeScript quiz?+

30 questions, with a 60-minute time limit. Every question includes a written explanation of the correct answer.

Is this TypeScript quiz free?+

Yes. Every quiz on CodexQuizz is free and needs no account. You only enter a name if you choose to post your score to the leaderboard.

What level is the intermediate quiz aimed at?+

Explore generics, enums, and more advanced type manipulations.

Can I use this to prepare for a TypeScript interview?+

Yes. The questions cover the topics that come up in TypeScript technical screens, and the explanations are written so that a wrong answer still teaches you the underlying concept.

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