Question 1

What are props in Vue and how do you validate them?

Accepted Answer

**Target Audience:** Vue beginners who have built a component or two and now need them to accept configuration from a parent.
**Difficulty:** Easy

> **How to read this doc:** Plain language first, then `📌 Interview term:` callouts. Every warning message, rendered value and production-build result quoted below came from running the code on Vue 3.5.44, compiled with `@vue/compiler-sfc` and mounted in jsdom, in development and production mode.

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

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Question 2

How does v-model work on form inputs?

Accepted Answer

**Target Audience:** Vue beginners building their first forms. Assumes HTML form elements and a little JavaScript.
**Difficulty:** Easy

> **How to read this doc:** Plain language first, then `📌 Interview term:` callouts. Every state dump, compiler snippet and compiler error below came from running Vue 3.5.44: templates compiled with `@vue/compiler-sfc` / `@vue/compiler-dom`, mounted in jsdom, with a driver typing, clicking and selecting.

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

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Question 3

How do defineProps and defineEmits work in <script setup>?

Accepted Answer

**Target Audience:** Vue 3 developers using `<script setup>` who want to understand the two macros they write in almost every component.
**Difficulty:** Easy

> **How to read this doc:** Plain language first, then `📌 Interview term:` callouts. All compiled output and compiler errors come from `@vue/compiler-sfc` 3.5.44 `compileScript()`; runtime logs from a two-component app compiled the same way and mounted in jsdom; type errors from `vue-tsc` 3.3.13.

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

Question 4

What are provide and inject?

Accepted Answer

**Target Audience:** Anyone preparing for a Vue interview. Assumes you know props and `ref()`. **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 "Verified" sections was produced on Vue 3.5.44: the runnable example with the repo verifier (compiled and mounted in jsdom), the app-level behaviour with a Node script against the sam

Question 5

How do you handle forms and validation in Vue?

Accepted Answer

**Target Audience:** Anyone preparing for a Vue interview who knows [how v-model works on inputs](/interview-question/how-does-v-model-work-on-form-inputs) — no form library experience required. **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 was produced on Vue 3.5.44 by mounting the components in jsdom with the repo verifier and

Question 6

What is the difference between computed and watch?

Accepted Answer

**Target Audience:** Vue developers who use both APIs and want a crisp rule for choosing, plus the reasons behind it. **Difficulty:** Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts with the precise vocabulary. Every output below was produced on Vue 3.5.44: the probes with node, the component by compiling it with @vue/compiler-sfc and typing into it in jsdom. ## 1. Why This Even Matters — A Story First A café has

Question 7

When should you use shallowRef / shallowReactive / triggerRef?

Accepted Answer

**Target Audience:** Vue developers making performance or architecture decisions about reactive state. **Difficulty:** Hard > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. Timings and outputs below come from running the code on Vue 3.5.44 (Node 22, and jsdom for the component). Timings are from one sandbox machine and will differ on yours; the ratios are the point. For the mechanics of the shallow APIs themselves (what is tracked, ref unwrapping,

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