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 the difference between v-if and v-show?

**Target Audience:** Beginners who have used v-if or v-show and want to know which to pick. Basic HTML and CSS assumed. **Difficulty:** Easy > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. Every DOM snapshot, lifecycle log and timing below was produced by mounting the code on Vue 3.5.44 in jsdom. The timings are jsdom numbers, useful for comparing the two directives with each other, not as real-browser figures. ## 1. Wh

Question 1

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 2

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 3

What is the difference between v-if and v-show?

Accepted Answer

**Target Audience:** Beginners who have used v-if or v-show and want to know which to pick. Basic HTML and CSS assumed. **Difficulty:** Easy > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. Every DOM snapshot, lifecycle log and timing below was produced by mounting the code on Vue 3.5.44 in jsdom. The timings are jsdom numbers, useful for comparing the two directives with each other, not as real-browser figures. ## 1. Wh

Question 4

What are Vue Router navigation guards?

Accepted Answer

**Target Audience:** Anyone preparing for a Vue interview who knows [basic router setup](/interview-question/how-do-you-set-up-vue-router-routes-routerlink-routerview-history-modes) — no guard 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. The guard order in section 4 was printed by a Node script with console.log

Question 5

When should you use readonly, markRaw, and toRaw in Vue reactivity?

Accepted Answer

**Target Audience:** Vue developers designing composables and stores, or integrating non-Vue libraries. **Difficulty:** Medium > **How to read this doc:** Plain language first, then 📌 Interview term: callouts. Warnings, outputs and timings below come from running code on Vue 3.5.44 (Node 22, and jsdom for the component); timings are from one sandbox machine. This page is the **decision guide**. The mechanics are covered by two sibling questions: [What does readonly do in Vue's rea

VUE.JSDECODED.

Easy

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

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

What is the difference between v-if and v-show?

Medium

What are Vue Router navigation guards?

When should you use readonly, markRaw, and toRaw in Vue reactivity?