Q: Can a computed property be writable?

**Target Audience:** Vue developers who know read-only computed and want to know when a writable one is the right tool. **Difficulty:** Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts with the vocabulary an interviewer expects. All output below was produced on Vue 3.5.44: the probe with node , the type errors with TypeScript 5 against Vue's own typings, and the component by compiling it with @vue/compiler-sfc<

Q: How do you handle forms and validation in Vue?

**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 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 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 3

What changed from Vue 2 to Vue 3, and what does Vue 2 end of life mean?

Accepted Answer

**Target Audience:** Developers who meet Vue 2 code at work, or see Vue 2 tutorials online, and need to explain what is different in Vue 3. Basic Vue knowledge helps but every term is defined. **Difficulty:** Easy > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. The comparisons in sections 4 and 5 were not taken from the migration guide: the same code was run on **vue 2.7.16** and **vue 3.5.44** side by side in Node with jsdom, and the outputs are

Question 4

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

Picture a

Question 5

What are v-model modifiers?

Accepted Answer

**Target Audience:** Vue developers who already use `v-model` on inputs and want to control when and how values are stored.
**Difficulty:** Easy

> **How to read this doc:** Plain language first, then `📌 Interview term:` callouts. Every value shown below was read from component state after a driver focused, typed into and blurred real inputs, on Vue 3.5.44 compiled with `@vue/compiler-sfc` and mounted in jsdom.

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

Think of a receptionist taking phone m

Question 6

What is defineModel() in Vue 3.4+ and how does it replace manual prop + emit?

Accepted Answer

**Target Audience:** Vue 3 developers who know the [component v-model contract](/interview-question/how-does-v-model-work-on-components) and want to know what `defineModel()` really does.
**Difficulty:** Medium

> **How to read this doc:** Plain language first, then `📌 Interview term:` callouts. The compiled output is from `@vue/compiler-sfc` 3.5.44 `compileScript()`, and every value read after a click or keystroke came from mounting the components in jsdom on Vue 3.5.44. Version history comes

Question 7

How does v-model work on components?

Accepted Answer

**Target Audience:** Vue developers who use `v-model` on inputs and now need their own components to support it.
**Difficulty:** Medium

> **How to read this doc:** Plain language first, then `📌 Interview term:` callouts. The compiled output, warnings, compiler errors and the state after typing that are quoted below all came from Vue 3.5.44, compiled with `@vue/compiler-dom` and `@vue/compiler-sfc` and mounted in jsdom.

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

A hotel guest wants a differe

Question 8

Can a computed property be writable?

Accepted Answer

**Target Audience:** Vue developers who know read-only computed and want to know when a writable one is the right tool. **Difficulty:** Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts with the vocabulary an interviewer expects. All output below was produced on Vue 3.5.44: the probe with node, the type errors with TypeScript 5 against Vue's own typings, and the component by compiling it with @vue/compiler-sfc<

Question 9

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 10

What is defineExpose() and why are <script setup> components closed by default?

Accepted Answer

**Target Audience:** Vue developers who know template refs and are moving from the Options API to `

VUE.JSDECODED.

Easy

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

What are Vue directives? Give common examples.

What changed from Vue 2 to Vue 3, and what does Vue 2 end of life mean?

How does v-model work on form inputs?

What are v-model modifiers?

Medium

What is defineModel() in Vue 3.4+ and how does it replace manual prop + emit?

How does v-model work on components?

Can a computed property be writable?

How do you handle forms and validation in Vue?

What is defineExpose() and why are <script setup> components closed by default?

How do Vue components communicate?

Hard

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

What is a custom renderer in Vue (createRenderer)?