Q: What is v-html and what is the risk of using it?

**Target Audience:** Beginners who have seen v-html in a codebase, or are tempted to use it. Basic HTML assumed; no security background needed. **Difficulty:** Easy > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. The rendered HTML was produced by mounting the example on Vue 3.5.44 in jsdom and with renderToString . Because jsdom does not load images (so an onerror payload can never fire there), the attack its

Question 1

What is Vue.js and what are its core features?

Accepted Answer

**Target Audience:** Complete beginners preparing for a first Vue interview. Assumes you know a little HTML and JavaScript, nothing about Vue or any other framework. **Difficulty:** Easy > **How to read this doc:** Every idea is explained in plain language first, then tagged with 📌 Interview term: so you also learn the exact words an interviewer listens for. The outputs in sections 5 and 6 were produced by actually compiling and running the code on Vue 3.5.44, the current stable r

Question 2

What is v-html and what is the risk of using it?

Accepted Answer

**Target Audience:** Beginners who have seen v-html in a codebase, or are tempted to use it. Basic HTML assumed; no security background needed. **Difficulty:** Easy > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. The rendered HTML was produced by mounting the example on Vue 3.5.44 in jsdom and with renderToString. Because jsdom does not load images (so an onerror payload can never fire there), the attack its

Question 3

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 4

What are Vue directives? Give common examples.

Accepted Answer

**Target Audience:** Beginners who can read a basic Vue template and want to understand every v- attribute they see. Basic HTML and JavaScript assumed. **Difficulty:** Easy > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. The rendered output, the compiled render function and the warnings below come from compiling and mounting the example on Vue 3.5.44, not from memory. ## 1. Why This Even Matters — A Story First Imagine a theatre sc

Question 5

What are dynamic arguments and v-bind shorthand?

Accepted Answer

**Target Audience:** Vue beginners who know what `v-bind` and `v-on` do and want the full picture of their syntax.
**Difficulty:** Easy

> **How to read this doc:** Plain language first, then `📌 Interview term:` callouts. The compiled code, compiler errors, runtime errors and DOM output below came from running Vue 3.5.44 (`@vue/compiler-dom` for compiler output, jsdom for the runtime).

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

Think of a label maker at a warehouse. Normally the operator typ

Question 6

How do you render lists with v-for?

Accepted Answer

**Target Audience:** Beginners who need to show a list of things (products, messages, todos) in a Vue component. Basic JavaScript arrays and objects assumed. **Difficulty:** Easy > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. Every rendered list, DOM-identity check and error message below came from mounting the code on Vue 3.5.44 in jsdom and clicking through it. ## 1. Why This Even Matters — A Story First Imagine you are writing place cards f

Question 7

What is Vue template syntax (interpolation, directives, expressions)?

Accepted Answer

**Target Audience:** Beginners who know basic HTML and JavaScript and are reading Vue templates for the first time. **Difficulty:** Easy > **How to read this doc:** Plain language first, then 📌 Interview term: callouts with the precise vocabulary. Every rendered output, compiled render function, warning and error message below was produced by running the code on Vue 3.5.44 (@vue/compiler-dom for compiler output, the repo verifier for mounted components). ## 1. Why Th

Question 8

What is the difference between ref and reactive?

Accepted Answer

**Target Audience:** Developers who have written a Vue 3 component or two and want to stop guessing between ref and reactive. **Difficulty:** Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts with the vocabulary interviewers expect. Every output below was produced on Vue 3.5.44: the reactivity probe with node, the component by compiling it with @vue/compiler-sfc and clicking through it in js

Question 9

How do you make provide/inject type-safe?

Accepted Answer

**Target Audience:** Vue developers using TypeScript. Assumes you know what [provide and inject](/interview-question/what-are-provide-and-inject) do; this doc is only about typing them. **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 type errors quoted here are the real output of vue-tsc 3.3.13 on Vue 3.5.44, and the runtime ou

Question 10

What is a Vue plugin?

Accepted Answer

**Target Audience:** Vue developers who install libraries with `app.use()` and want to write their own.
**Difficulty:** Medium

> **How to read this doc:** Plain language first, then `📌 Interview term:` callouts. The plugin, the component that uses it and `main.js` were bundled with esbuild and run in jsdom on Vue 3.5.44; every log line and warning below is that run's real output. API availability was checked against the published `@vue/runtime-core` type definitions.

## 1. Why This Even Matte

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Easy

What is Vue.js and what are its core features?

What is v-html and what is the risk of using it?

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

What are Vue directives? Give common examples.

What are dynamic arguments and v-bind shorthand?

How do you render lists with v-for?

What is Vue template syntax (interpolation, directives, expressions)?

Medium

What is the difference between ref and reactive?

How do you make provide/inject type-safe?

What is a Vue plugin?

How do you use TypeScript with Vue (typed props, emits, refs, vue-tsc)?

Hard

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

How does the Vue compiler optimize templates (static hoisting, patch flags, block tree)?

What is a custom renderer in Vue (createRenderer)?

How does server-side rendering work in Vue (renderToString, hydration)?