From 5d64199bb6d5a875206cdcc552cdcb4bf32c7e97 Mon Sep 17 00:00:00 2001
From: Chad Fawcett <me@chadf.ca>
Date: Thu, 12 May 2016 17:02:07 -0700
Subject: [PATCH] Add information on JSX element keys (#6751)

---
 docs/docs/02.3-jsx-gotchas.md | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/docs/docs/02.3-jsx-gotchas.md b/docs/docs/02.3-jsx-gotchas.md
index 10ae6bcf0c..ce6deee711 100644
--- a/docs/docs/02.3-jsx-gotchas.md
+++ b/docs/docs/02.3-jsx-gotchas.md
@@ -40,10 +40,10 @@ A safer alternative is to find the [unicode number corresponding to the entity](
 <div>{'First ' + String.fromCharCode(183) + ' Second'}</div>
 ```
 
-You can use mixed arrays with strings and JSX elements.
+You can use mixed arrays with strings and JSX elements. Each JSX element in the array needs a unique key.
 
 ```javascript
-<div>{['First ', <span>&middot;</span>, ' Second']}</div>
+<div>{['First ', <span key="middot">&middot;</span>, ' Second']}</div>
 ```
 
 As a last resort, you always have the ability to [insert raw HTML](/react/tips/dangerously-set-inner-html.html).