Why is this reduce based array sum not working (JS)?

November 26, 2022

I’ve checked the answer to a similar question, but it doesn’t quite solve it and I had to count on your help/expertise:

let qties = [
  [12, 45, 56, "", 45, "", "", ""]
]
const incomingBulkQty = qties[0].reduce((partialSum, a) => partialSum + a, 0);
console.log('Result: ' + incomingBulkQty)

Result should be 158

I have to identify the elements’ indexes as such, given my real world context.

Thanks!

>Solution :

Once you add an empty string, the number is converted to a string and you’re just doing subsequent string concatenation.

Here we can just wrap in Number since the string is always an empty string. Otherwise we’d also have to do an isNaN check.

let qties = [
  [12, 45, 56, "", 45, "", "", ""]
]
const incomingBulkQty = qties[0].reduce((partialSum, a) => partialSum + Number(a), 0);
console.log('Result: ' + incomingBulkQty)