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JavaScript React Basics (2018) Introducing Props Iterating and Rendering with map()

Micah Cleveland
Micah Cleveland
633 Points

Question answered later on in the video.

App Updated Code:

const App = (props) => { return ( <div className="scoreboard"> <Header title="Scoreboard" totalPlayers={3} />

        { props.initialPlayers.map( playerObj =>  


Note: copied the list of players from teachers notes assigning them to a constant variable and using square brackets.

Full Error: react_devtools_backend.js:4026 Warning: Each child in a list should have a unique "key" prop.

Check the render method of App. See https://fb.me/react-warning-keys for more information. in Player (created by App) in App

Mark Sebeck
Mark Sebeck
Treehouse Moderator 37,329 Points

Great job figuring it out and thanks for updating the question. Will be great for other students with the same question. I marked your answer Best for you

2 Answers

Micah Cleveland
Micah Cleveland
633 Points

This was just a warning however I was curious. I was able to get rid of the warning by adding a key attribute w/ unique value to the <Player /> element.