For now I suggest using lodash functions exported as modules.

For example: https://www.npmjs.com/package/lodash.mean

Or, in light of `left-pad`: https://www.npmjs.com/package/lodash.padstart

You get the benefit of a "small, focused" module but still rely on a large and stable project with a great maintainer that cares about performance and testability.

There's already `Array.prototype.reduce()` in most browsers, which will do summing, string concatenation, and any other kind of aggregation:

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...

If you need something more convenient I highly recommend just adding lodash and getting a whole bag of rock-solid awesome tools.

reduce isn't a safe way to add floating-point numbers unless your accumulator is much more precise than your array values. You'll end up with what they call "catastrophic cancellation".

And they won't let you have fixed-point in JavaScript!

Doesn't a for loop have the same problem?

If you write the loop yourself, you can add everything to a double instead of a float, or a long double instead of a double, if you have those.

Oh, if all your numbers are positive you can also sort the array and it will minimize the error accumulated, but I'm not sure what to do with mixed signs.

here is the source for that npm package

https://github.com/bytespider/average/blob/master/src/averag...

and here is the code copied out in full

module.exports = function average(values) { for (var i = 0, sum = 0; i < values.length; ++i) { sum += values[i]; } return sum / values.length; };

is this worth adding a dependency to your build for?