Q131. How to loop inside JSX?
You can simply use `Array.prototype.map` with ES6 _arrow function_ syntax. For example, the `items` array of objects is mapped into an array of components: ```jsx harmony...
Technical Question Bank · Peer-Reviewed
Job Interview Questions and Answers Directory
Search and filter frequently asked interview questions across technical, programming, and behavioral domains. Tailor your interview preparation by difficulty for freshers or experienced developers (780 available).
Active:
Tag: js ×
Q132. What is the purpose of next-compose-plugins?
**`next-compose-plugins`** was a popular community utility library used in older Next.js projects to cleanly chain and compose multiple configuration plugins in `next.con...
Q133. Why do we need callbacks?
The callbacks are needed because javascript is an event driven language. That means instead of waiting for a response, javascript will keep executing while listening for ...
Q134. How do you access props in attribute quotes?
React (or JSX) doesn't support variable interpolation inside an attribute value. The below representation won't work: ```jsx harmony ``` But you can put any JS expression...
Q135. How do you add polyfills in Next.js?
Next.js automatically provides polyfills for widely used modern ECMAScript features (such as `Promise`, `fetch`, `Object.assign`, `Symbol`, and `URL`) targeting browsers ...
Q136. What is a callback hell?
Callback Hell is an anti-pattern with multiple nested callbacks which makes code hard to read and debug when dealing with asynchronous logic. The callback hell looks like...
Q137. What is static optimization in Next.js?
**Automatic Static Optimization** is a core Next.js feature where the build system automatically analyzes each page to determine whether it can be pre-rendered as pure st...
Q138. What are server-sent events?
Server-sent events (SSE) is a server push technology enabling a browser to receive automatic updates from a server via HTTP connection without resorting to polling. These...
Q139. How to conditionally apply class attributes?
You shouldn't use curly braces inside quotes because it is going to be evaluated as a string. ```jsx harmony ``` Instead you need to move curly braces outside (don't forg...
Q140. How do you handle internationalization (i18n) in Next.js?
By configuring i18n settings in next.config.js. ```js module.exports = { i18n: { locales: ["en", "fr"], defaultLocale: "en", }, }; ```