From 4adc854d6daa21fa90d44b586b90147b07de5d9a Mon Sep 17 00:00:00 2001 From: Matthew Holman Date: Fri, 24 Nov 2017 22:39:19 -0600 Subject: [PATCH] Added link explaining danger of using index as key --- content/docs/lists-and-keys.md | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/content/docs/lists-and-keys.md b/content/docs/lists-and-keys.md index 4c3f3cf6..1ad265ee 100644 --- a/content/docs/lists-and-keys.md +++ b/content/docs/lists-and-keys.md @@ -130,7 +130,7 @@ const todoItems = todos.map((todo, index) => ); ``` -We don't recommend using indexes for keys if the order of items may change. This can negatively impact performance and may cause issues with component state. If you choose not to assign a key to your list items then React will use indexes as keys. You may read an [in-depth explanation about why keys are necessary](/docs/reconciliation.html#recursing-on-children) if you're interested in more information. +We don't recommend using indexes for keys if the order of items may change. This can negatively impact performance and may cause issues with component state. You may read Robin Pokorny's article for an [in-depth explanation on the negative impacts of using an index as a key](https://medium.com/@robinpokorny/index-as-a-key-is-an-anti-pattern-e0349aece318). If you choose not to assign a key to your list items then React will use indexes as keys. You may read an [in-depth explanation about why keys are necessary](/docs/reconciliation.html#recursing-on-children) if you're interested in more information. ### Extracting Components with Keys