How can I insert array in the middle of another array in es6?

Question

I have two arrays:

let a = [1, 3, 5];
let b = [2, 4];

I need to put second array into first one after second element, so this is result:

[1, 3, 2, 4, 5]

What is the best way to insert second array into first in es6?

It can be easily solved using concat operation, but I am looking for nice way of doing it in es6.

I need to put second array at specific position, not in the end. — ruslan5t, Jan 13 '17 at 16:29
@ruslan5t, please refer to [How to ask](http://stackoverflow.com/help/how-to-ask). It's easier to help if you give us all required criteria at the beginning, instead of editing the question and changing your issue later. — Wiktor Bednarz, Jan 13 '17 at 16:42

Wiktor Bednarz · Accepted Answer · 2017-01-13T16:33:14.680

5

If you want to insert the second array at specific index, you can use splice function and spread operator.

var a = [1, 3, 5];
var b = [2, 4, 6];

a.splice(2, 0, ...b);

console.log(a); // [1, 3, 2, 4, 6, 5]

edited Jan 13 '17 at 16:33

answered Jan 13 '17 at 16:25

Wiktor Bednarz

I need to put second array in the middle of first one, not in the end. – ruslan5t Jan 13 '17 at 16:30
1

@ruslan5t, I updated my answer to better fit your question. – Wiktor Bednarz Jan 13 '17 at 16:34
2

[`...` is not an operator](http://stackoverflow.com/a/37152508/218196). You could use the term *spread argument*. – Felix Kling Jan 13 '17 at 16:44

Pranav C Balan · Answer 2 · 2017-01-13T16:44:55.683

2

a.splice(2, 0, ...b)

let a = [1, 2, 5];
let b = [3, 4];

a.splice(2, 0, ...b);

console.log(a);

edited Jan 13 '17 at 16:44

answered Jan 13 '17 at 16:24

Pranav C Balan

I don't want to sort arrays, I need to put second one in first one at specific position. – ruslan5t Jan 13 '17 at 16:29
[`...` is not an operator](http://stackoverflow.com/a/37152508/218196). You could use the term *spread argument*. – Felix Kling Jan 13 '17 at 16:44
1

@FelixKling : sorry , I just updated :) ... thanks for the correction – Pranav C Balan Jan 13 '17 at 16:45

score 0 · Answer 3 · edited Dec 13 '22 at 05:09

0

I think this is the answer you're looking for:

function frankenSplice(arr1, arr2, n) {
    let arr3 = [...arr2];
    arr3.splice(n, 0, ...arr1);
    return arr3;
}

edited Dec 13 '22 at 05:09

shieldgenerator7

answered Jul 14 '18 at 08:31

3 Answers3