Q: useAttrs() vs $attrs — how do you handle fallthrough attributes in composition API?

**Target Audience:** Vue developers moving to ` ` and the Composition API. Assumes you know what [fallthrough attributes ($attrs)](/interview-question/what-are-fallthrough-attributes-attrs) are; that sibling question covers the inheritance rules themselves. **Difficulty:** Medium > **How to read this doc:** Ideas are explained in plain language first, then tagged with 📌 Interview term: so you also learn the words an interviewer listens for. Every output in the "Verifi

Question 1

What do defineOptions() and defineSlots() do in <script setup>?

Accepted Answer

**Target Audience:** Vue developers using `<script setup>` who want the remaining component options and typed slots.
**Difficulty:** Medium

> **How to read this doc:** Plain language first, then `📌 Interview term:` callouts. The compiler output and every error message below come from running `@vue/compiler-sfc` 3.5.44; the runnable example was mounted in jsdom; the type errors come from `vue-tsc` 3.3.13. The version claims were checked against the published `@vue/runtime-core` type definitions

Question 2

How do Vue components communicate?

Accepted Answer

**Target Audience:** Anyone preparing for a Vue interview. Assumes basic JavaScript; no prior Vue knowledge needed. **Difficulty:** Medium > **How to read this doc:** Ideas are explained in plain language first, then tagged with 📌 Interview term: so you also learn the words an interviewer listens for. Every output quoted in the "Verified" sections was produced by running the code on Vue 3.5.44, either with the repo verifier (compiled with @vue/compiler-sfc and mounted

Question 3

What are slots in Vue?

Accepted Answer

**Target Audience:** Anyone preparing for a Vue interview. Assumes you know what a component and a prop are. **Difficulty:** Medium > **How to read this doc:** Ideas are explained in plain language first, then tagged with 📌 Interview term: so you also learn the words an interviewer listens for. The outputs in the "Verified" sections were produced on Vue 3.5.44: the runnable example with the repo verifier (compiled and mounted in jsdom), the SFC versions with Vitest and Vue Test Ut

Question 4

useAttrs() vs $attrs — how do you handle fallthrough attributes in composition API?

Accepted Answer

**Target Audience:** Vue developers moving to `

Question 5

How do dynamic components work?

Accepted Answer

**Target Audience:** Developers who know basic Vue templates and components and want to understand runtime component switching. **Difficulty:** Medium > **How to read this doc:** Ideas are explained in plain language first, then tagged with 📌 Interview term: so you also learn the words an interviewer listens for. Every output block in this doc was produced by compiling and running the code on Vue 3.5.44, either with the repo's verify-vue-example.mjs harness (compile t

Question 6

How do generic <script setup> components work (generic="T")?

Accepted Answer

**Target Audience:** Vue and TypeScript developers who build reusable components such as lists, tables and selects.
**Difficulty:** Hard

> **How to read this doc:** Plain language first, then `📌 Interview term:` callouts. All type errors below are real output from `vue-tsc` 3.3.13 (TypeScript 5.9, `strict: true`) run on the example files; the compiled output comes from `@vue/compiler-sfc` 3.5.44; the runnable example was mounted in jsdom on Vue 3.5.44.

## 1. Why This Even Matters — A Story Fi

VUE.JSDECODED.

Medium