Sum negative and positive numbers in array to get a result

Question

i'm stucked with a simple logic, i have an array as a result that contains positive and negative numbers.

what i need is to sum both negative and positive and print a result

const arr = ['-8', '-3', '1', '-4', '0']
// expected results = -14

what i've tried so far is to separate negative and positive with:

 const positive = scores.filter(posNumber => posNumber >= 0)
 const negative = scores.filter(negNumber => negNumber < 0)

but if i perform a reduce on positive i get "010" as a result....

Ow those aren't integers, try converting them to integers before doing any maths with them — 0stone0, Apr 22 '22 at 16:16

score 3 · Accepted Answer · answered Apr 22 '22 at 16:18

The problem here is that your array is actually an array of strings instead of numbers. So in reality, you need to convert the array to an array of numbers and then you can sum the values.

const arr = ['-8', '-3', '1', '-4', '0'];
const sum = arr.reduce((acc, value) => acc + Number(value), 0); // -14

Cam · Answer 2 · 2022-04-22T16:26:41.940

2

Those are strings. You need to convert them to Numbers first:

const arr = ['-8', '-3', '1', '-4', '0'].map(Number);
const positive = arr.filter(posNumber => posNumber >= 0);
const negative = arr.filter(negNumber => negNumber < 0);
const positiveSum = positive.reduce((sumSoFar, current) => sumSoFar + current, 0);
const negativeSum = negative.reduce((sumSoFar, current) => sumSoFar + current, 0);

Or just

const arr = ['-8', '-3', '1', '-4', '0'].map(Number);
const sum = arr.reduce((sumSoFar, current) => sumSoFar + current, 0);

for the overall sum.

edited Apr 22 '22 at 16:26

answered Apr 22 '22 at 16:16

Cam

14,930
16
77
128

.......how is possible that i'm totally blind............ – MarkLearningCode Apr 22 '22 at 16:17

score 0 · Answer 3 · answered Apr 22 '22 at 16:23

0

   let sum = 0
    arr.forEach(s => sum+= +s) 
     console.log(sum)

"+s" convert the value to an integer. You can use parseInt

answered Apr 22 '22 at 16:23

labs

790
6
8

score 0 · Answer 4 · answered Apr 22 '22 at 16:25

0

To piggyback off of Luís, once the strings are converted to integers, there's no need to break out the positive from the negative if you're just looking for the overall sum.

answered Apr 22 '22 at 16:25

Blackard

85
10

score 0 · Answer 5 · answered Apr 22 '22 at 16:31

0

You can use parseInt to convert string to a number and then do the sum.

let sum = arr.reduce((accum,each)=>{ 
accum = accum + parseInt(each);
return accum;
},0);

answered Apr 22 '22 at 16:31

santhini s

41
2

Sum negative and positive numbers in array to get a result

5 Answers5