Divide array based on inner array conditions

Question

I have an array like :

let colors=[ [ 31236780195925 ],[],[],[],[],[ 31236780163157 ],[],[],[ 31236780228693 ],[],[],[],[],[] ]

inner array values can differ, I want result like in the following structure

let Red=[[ 31236780195925 ],[],[],[],[]];
let Green=[[ 31236780163157 ],[],[]];
let Blue=[[ 31236780228693 ],[],[],[],[],[]];

Hi! Please read through the help center, in particular How do I ask a good question? Your best bet here is to do your research, search for related topics on SO, and give it a go. If you get stuck and can't get unstuck after doing more research and searching, post a minimal reproducible example of your attempt and say specifically where you're stuck. People will be glad to help. — T.J. Crowder
– T.J. Crowder, Commented Nov 28, 2019 at 13:23
from one value contain inner array to next value contain inner array — Zain
– Zain, Commented Nov 28, 2019 at 13:23

Aksen P · Accepted Answer · 2019-11-29 06:47:12Z

2

You can use the following solution. It checks length of each element and if it becomes more then 0 it starts to fill next index. Red has [0] index, Green has [1] index, Blue has [2] index of resultant array.

var colors=[ [31236780195925],[],[],[],[],[ 31236780163157 ],[],[],[ 31236780228693 ],[],[],[],[],[] ];

var res_ar = []; 
var i = -1;
 
colors.forEach(ar => {
      if (ar.length > 0) {
        i++;
        res_ar.push([]);
      }
        res_ar[i].push(ar); 
})

  // console.log(res_ar) 

console.log(res_ar[0]);
console.log(res_ar[1]);
console.log(res_ar[2]);

edited Nov 29, 2019 at 6:47

answered Nov 28, 2019 at 14:39

Aksen P

4,6153 gold badges16 silver badges27 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Zeyad · Accepted Answer · 2019-11-28 14:35:29Z

1

I just implemented it using reduce and destructuring:

const [R, G, B] = colors.reduce((acc, cur, indx) => {
    if(cur.length && indx === 0 ) {
        acc.push([cur]);
    } else if(!cur.length) {
        acc[acc.length - 1].push(cur);
    } else {
        acc.push([cur]);
    }

return acc;
}, []);

answered Nov 28, 2019 at 14:35

Zeyad

2,5685 gold badges28 silver badges45 bronze badges

Comments

Luïs · Accepted Answer · 2019-11-28 13:52:44Z

If you always want to extract an RGB value, and thus have 3 values in your colors array. You could do something like this:

const colors = [[31236780195925], [], [], [], [], [31236780163157], [], [], [31236780228693], [], [], [], [], []];
const indexes = [];

colors.forEach((color, index) => {
    if (color.length > 0) {
        indexes.push(index);
    }
});

const red = colors.slice(indexes[0], indexes[1]);
const green = colors.slice(indexes[1], indexes[2]);
const blue = colors.slice(indexes[2]);

The first loop creates an array of indexes of every array in your colors variable which isn't empty.
You can then .slice your array at those indexes to split them apart.

In case you want a more dynamic approach. You could loop over your colors array again and use those indexes to create a new nested array:

const slicedColors = [];

colors.forEach((color, index) => {
    if (color.length > 0) {
        const nextColorIndex = indexes[indexes.indexOf(index) + 1];
        slicedColors.push(colors.slice(index, nextColorIndex));
    }
});

const red = slicedColors[0];
const green = slicedColors[1];
const blue = slicedColors[2];

Collectives™ on Stack Overflow

Divide array based on inner array conditions

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related