---
title: "Discussion on \"Why Using Index as Key in React.js Map Function Can Cause Problems and How to Fix Them\" | Hashnode"
description: "Discussion on \"Why Using Index as Key in React.js Map Function Can Cause Problems and How to Fix Them\". Discover the problem with using index as a key in a React.js map function and how using unique keys can improve performance and make you a better developer."
url: "https://hashnode.com/posts/why-using-index-as-key-in-reactjs-map-function-can-cause-problems-and-how-to-fix-them/643422c75e2a2fde5b19c9f2"
---

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Discussion

# [Why Using Index as Key in React.js Map Function Can Cause Problems and How to Fix Them](https://blog.anja-stricker.de/why-using-index-as-key-in-reactjs-map-function-can-cause-problems-and-how-to-fix-them?utm_source=hashnode&utm_medium=feed)

Discover the problem with using index as a key in a React.js map function and how using unique keys can improve performance and make you a better developer.

Apr 10, 2023 · 3 min read · blog.anja-stricker.de  
Read the article

-   [#reactjs](https://hashnode.com/tag/reactjs)
-   [#mapping](https://hashnode.com/tag/mapping)
-   [#performance-optimization](https://hashnode.com/tag/performance-optimization)
-   [#indexing](https://hashnode.com/tag/indexing)
-   [#list](https://hashnode.com/tag/list)

## Written by

[Anja Stricker](https://hashnode.com/@TechPiranja)

@TechPiranja · Germany

  
[View profile](https://hashnode.com/@TechPiranja)

I am a fullstack software developer! I love react / react native and coding with Typescript!

## Responses 2

Markdown supported · ⌘↵ to post

[Manoj](https://hashnode.com/@manu741)

[May 2, 2024](https://hashnode.com/posts/why-using-index-as-key-in-reactjs-map-function-can-cause-problems-and-how-to-fix-them/643422c75e2a2fde5b19c9f2/comment/6633494dfb396271802b0611)

Thanks for sharing when I read the react doc's i understood it differently. Now it was clear.

[Damilola Esan](https://hashnode.com/@Ionikdev)

[Apr 10, 2023](https://hashnode.com/posts/why-using-index-as-key-in-reactjs-map-function-can-cause-problems-and-how-to-fix-them/643422c75e2a2fde5b19c9f2/comment/64344ad047aba44dec0c199f)

Thank you for sharing this really helps🙌

[Anja Stricker](https://hashnode.com/@TechPiranja)

[Apr 10, 2023](https://hashnode.com/posts/why-using-index-as-key-in-reactjs-map-function-can-cause-problems-and-how-to-fix-them/643422c75e2a2fde5b19c9f2/comment/64344ad047aba44dec0c199f#reply-64344d2847aba44dec0c1a17)

I‘m glad you liked it! 🙌