Expand elements of array split by comma

Question

Say I have the following array:

const arr = [ 'a,b,c', 'd,e,f', 'g,h,i' ];

I want to get to

[ 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i' ]

arr.reduce((a,c) => (typeof a == 'object' ? a : a.split(',')).concat(c.split(',')));

But I wonder if there is a better way to do this.

In a future js version itll be `arr.flatMap(el => el.split(","));` — Jonas Wilms, Aug 18 '18 at 13:18

Mohammad Usman · Answer 1 · 2018-08-18T13:13:42.203

1

You can use .join() and .split() methods:

const arr = [ 'a,b,c', 'd,e,f', 'g,h,i' ];

const result = arr.join().split(",");

console.log(result);

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References:

edited Aug 18 '18 at 13:13

answered Aug 18 '18 at 13:11

Mohammad Usman

score 1 · Accepted Answer · answered Aug 18 '18 at 13:13

1

Use reduce method and split to split the string by comma

let m = ['a,b,c', 'd,e,f', 'g,h,i'];

let x = m.reduce(function(acc, curr) {
  acc.push(...curr.split(','))
  return acc;
}, [])
console.log(x)

answered Aug 18 '18 at 13:13

brk

Yes, I think this is the best solution. I had also come up with a version using push, but had overlooked the initial value arg, which simplifies it a lot. Going to accept your answer. – Austin France Aug 18 '18 at 13:29
My final version based on your answer was `arr.reduce((a, c) => (a.push(...c.split(',')),a), [])` – Austin France Aug 18 '18 at 13:35
Why not `arr.reduce((acc, el) => acc.concat(el.split(",")), [])` ? – Jonas Wilms Aug 18 '18 at 13:42
Because concat is needlessly creating copies of the array. – Austin France Aug 22 '18 at 13:15

score 0 · Answer 3 · answered Aug 18 '18 at 13:11

0

You do not need reduce for that just use join(',') and split(','):

const arr = [ 'a,b,c', 'd,e,f', 'g,h,i' ];
var res = arr.join(',').split(',');
console.log(res);

answered Aug 18 '18 at 13:11

Ankit Agarwal

score 0 · Answer 4 · answered Aug 18 '18 at 13:16

0

simply concat the splited subarray

const arr = [ 'a,b,c', 'd,e,f', 'g,h,i' ];
console.log( [].concat(...arr.map(a=>a.split(','))) )

answered Aug 18 '18 at 13:16

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4 Answers4