MongoDB $arrayElemAt
Read the array element at a particular position.
Indexes begin at `0`; negative indexes count backward from the end. This reads one value without unwinding the entire array.
Array expressions inspect or transform an array without creating a separate document for every element. These are supported in the playground for further practice.
Course use: Supported in the playground.
Example pipeline syntax
{ $arrayElemAt: ["$items", 0] }