---
title: "What is understanding unique keys for array children in React.js"  
description: "What is understanding unique keys for array children in React.js"  
author: "Erick Wilsom"  
published: 2022-10-27  
updated: 2022-10-27  
canonical: https://www.mindstick.com/forum/157181/what-is-understanding-unique-keys-for-array-children-in-react-js  
category: "node.js"  
tags: ["reactjs"]  
reading_time: 1 minute  

---

# What is understanding unique keys for array children in React.js

I'm [building](https://www.mindstick.com/blog/23088/which-tonewood-is-suitable-for-building-a-guitar) a [React component](https://www.mindstick.com/forum/159296/implement-a-react-component-that-manages-a-form-s-state-and-validates-user-inputs) that accepts a JSON [data source](https://www.mindstick.com/interview/808/what-is-a-data-source) and creates a sortable table. Each of the [dynamic data](https://www.mindstick.com/forum/2180/dynamic-data-in-repeater) rows has a [unique key](https://answers.mindstick.com/qa/116303/explain-database-primary-key-vs-unique-key) assigned to.

> Each child in an array should have a unique "key" prop. Check the render [method](https://www.mindstick.com/forum/166/webservice-method) of TableComponent.

## Replies

### Reply by Gourav Jangra

Your rows in JS array should have [unique](https://www.mindstick.com/blog/12870/how-to-be-unique-in-business) key property. It'll help ReactJS to find references to the appropriate DOM nodes and update only content inside mark-up but not re-render the whole table/row


---

Original Source: https://www.mindstick.com/forum/157181/what-is-understanding-unique-keys-for-array-children-in-react-js

Copyright © MindStick Software Pvt. Ltd. This Markdown version is provided for developers, AI systems, and offline reading.