Split ARRAY into chunks as they appear in sequence-CodePudding

I got an array of objects which I need to make into three chunks in the sequence as they are in the original array. For eg.

let arr = [{1},{2}, {3}, {4}, {5}, {6}, {7}, {8}, {9}, {10}];

This array needs to be split like this:

let newArray = {a:[{1},{4},{7},{10},...}], b:[{2},{5},{8}], c:[{3},{6},{9}]};

CodePudding user response：

Maybe this approach would be useful

const data = [{1:1}, {2:2}, {3:3}, {4:4}, {5:5}, {6:6}, {7:7}, {8:8}, {9:9}, {10:10}];

const chunk = (arr, n) => arr.length ? [arr.slice(0, n), ...chunk(arr.slice(n), n)] : [];

const chunks = chunk(data, 3);
const rotated = chunks[0].map((_, colIndex) => chunks.map(row => row[colIndex]));
const result = rotated.map((arr, index) => 
  ({ [index]: arr.filter(Boolean) }));

console.log(result);

.as-console-wrapper{min-height: 100%!important; top: 0}

CodePudding user response：

{1} is not a valid js structure

assuming than arr is an array of object you can :

generate a rolling char index with String.fromCharCode(current 97)
use an object to have char index

let arr = [{name:1},{name:2}, {name:3}, {name:4}, {name:5}, {name:6}, {name:7}, {name:8}, {name:9}, {name:10}];

function transform(theArray, chunkValue) {
  let finalObject = {};
  let current = 0;
  let currentIndex;
  
  theArray.forEach(element => {
    currentIndex = String.fromCharCode(current   97);
    if (!finalObject[currentIndex]) {
      finalObject[currentIndex] = [];
    }
    finalObject[currentIndex].push(element);
    current  ;
    if (current === chunkValue) {
      current = 0;
    }
  });
  
  console.log(finalObject);
  return finalObject;
}

transform(arr, 3);