Type Safety with ES2022's Array.prototype.at

Ben Asher
Ben Asher
Engineering

1 minute read

ES2022 introduces Array.prototype.at and we've come to love using it. Array.prototype.at can replace using the standard index operator []:

1const arr: number[] = [];
2
3arr[0].toString();
4
5// Same as above!
6arr.at(0).toString();

In the example above, even though index 0 may not have anything there, Typescript is happy to allow us to to call toString(). With .at(), we get a compiler error:

Typescripts Compiler Error
Typescript's compiler error.

Array.prototype.at is not officially supported in all versions of Node. Check node.green to see if you can use it!

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