calculate JSON.stringify(obj) to sum value of string?

Question

In my local storage I have some score value stored in array

var obj = localStorage.getItem("scoreList")

output

[0,10,10,0,10]

I want sum of this value like and return to data value

sum = 30

I have tried to convert into string value

var string = JSON.stringify(obj);
output "[0,10,10,0,10]"

How can I execute this sum value ?

Yes it did answered – Tanvir Hasan Emon Apr 20 '22 at 18:40 — Tanvir Hasan Emon, Apr 20 '22 at 18:40

score 4 · Answer 1 · answered Apr 20 '22 at 18:15

4

[0,10,10,0,10].reduce((sum, a) => sum + a, 0);

answered Apr 20 '22 at 18:15

Satya S

228
1
6

MoRe · Accepted Answer · 2022-04-20T18:36:42.317

1

localStorage.getItem("scoreList").replace(/(\[|\])/g, '').split(",").map(x => parseFloat(x)).reduce((a,b) => a+b, 0)

a simple way:

JSON.parse(localStorage.getItem("scoreList")).reduce((x, y) => x + y)

edited Apr 20 '22 at 18:36

answered Apr 20 '22 at 18:16

MoRe

2,296
2
3
23

const ttlsum= localStorage.getItem("scoreList").split(",").map(s => parseFloat(s)).reduce((x,y) => x+y) console.log(ttlsum); showed NaN value – Tanvir Hasan Emon Apr 20 '22 at 18:18
@TanvirHasanEmon I updated it, hope to work – MoRe Apr 20 '22 at 18:25
1

I did worked , thanks – Tanvir Hasan Emon Apr 20 '22 at 18:28
Hey need more help , in initial when string doesn't store any value then it's show Cannot read properties of null (reading 'replace') . after store value its worked fine – Tanvir Hasan Emon Apr 20 '22 at 19:48
did found answer. Have to use optional chaining (?.) to overcome this error – Tanvir Hasan Emon Apr 20 '22 at 20:02
1

@TanvirHasanEmon I saw your comments now and I'm glad to see you found your answer – MoRe Apr 20 '22 at 20:45

score 1 · Answer 3 · answered Apr 20 '22 at 18:19

1

If you set the scoreList value as an array, that is:

localStorage.setItem('scoreList', [0,10,10,0,10])

When you get it back it will still be a string, so there's no need for any other kind of validation or data type transformation as you did with JSON.stringfy. The following shoud be enough:

const obj = localStorage.getItem("scoreList")
const total = obj.reduce((sum, item) => sum + item, 0);
//total = 30

answered Apr 20 '22 at 18:19

Pelicer

1,348
4
23
54

it's show obj.reduce is not a function in my nuxt js appplication – Tanvir Hasan Emon Apr 20 '22 at 18:23

calculate JSON.stringify(obj) to sum value of string?

3 Answers3