There are several ways to compute the sum of numbers in an array with JavaScript. The approaches differ mainly in how readable they are — and readable code is easier to maintain and easier for others to understand and build on.

TL;DR​

• There are many ways to sum numbers in an array, but several of them are hard to read and unnecessarily complicated.
• The best way is using the built-in reduce function — or the newer Math.sumPrecise if you can rely on it being available.