What does .map() return? take an array of numbers and double their values.
If I want to loop through an array and display each value in JSX, how do I do that in React? build collections of elements and include them in JSX using curly braces {}.
Each list item needs a unique __.
Keys Keys help React identify which items have changed, are added, or are removed.
Increment operator adds one and returns a value
[Source] https://reactjs.org/docs/lists-and-keys.html [Source] https://medium.com/coding-at-dawn/how-to-use-the-spread-operator-in-javascript-b9e4a8b06fab