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

Q: What is a Single File Component (SFC)?

**Target Audience:** Beginners who have seen .vue files but do not know what is inside one or what happens to it. Basic HTML, CSS and JavaScript assumed. **Difficulty:** Easy > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. The compiled JavaScript and CSS in sections 5 and 6 are the real, unedited output of @vue/compiler-sfc 3.5.44, the same compiler @vitejs/plugin-vue calls during a Vite build. The runnable

Question 1

How do you handle events in Vue (v-on and event modifiers)?

Accepted Answer

**Target Audience:** Beginners wiring up buttons, forms and keyboard shortcuts in Vue. Basic DOM events (click, submit, keyup) assumed; no Vue experience needed. **Difficulty:** Easy > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. Every "what got logged" table, compiled handler and ordering claim below was produced by dispatching real DOM events at components mounted on Vue 3.5.44 in jsdom. ## 1. Why This E

Question 2

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 3

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 4

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

A coffe

Question 5

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 6

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 7

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 8

How do you bind classes and styles dynamically?

Accepted Answer

**Target Audience:** Anyone preparing for a Vue interview. Assumes basic HTML and CSS and a first look at Vue templates.
**Difficulty:** Easy

> **How to read this doc:** Plain language first, then `📌 Interview term:` callouts that give you the exact vocabulary. Every rendered class string, style attribute, warning and compiler line quoted below came from running the code on Vue 3.5.44 (compiled with `@vue/compiler-sfc`, mounted in jsdom).

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

Imagine a

Question 9

What is a Single File Component (SFC)?

Accepted Answer

**Target Audience:** Beginners who have seen .vue files but do not know what is inside one or what happens to it. Basic HTML, CSS and JavaScript assumed. **Difficulty:** Easy > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. The compiled JavaScript and CSS in sections 5 and 6 are the real, unedited output of @vue/compiler-sfc 3.5.44, the same compiler @vitejs/plugin-vue calls during a Vite build. The runnable

Question 10

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

VUE.JSDECODED.

Easy

How do you handle events in Vue (v-on and event modifiers)?

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?

How do you bind classes and styles dynamically?

Medium

How do <Transition>, <KeepAlive> and <Suspense> compose in Vue 3?

What is the difference between ref and reactive?

How do you make provide/inject type-safe?

What is a Vue plugin?

How do you access a DOM element or child component instance?

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

What is defineExpose?

What is the difference between computed and watch?

Hard

What is Vapor mode in Vue 3.5+ and how does it differ from the virtual DOM?

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

When should you choose Vapor over VDOM in a real app — trade-offs?

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)?