JSFiddle - React, Tailwind, and code Playground

by tymeJV

JavaScript

var arr1 = [ { _id: '1', sum: 100 }, { _id: '2', sum: 100 } ],
    arr2 =  [ { _id: '1', sum: 281.16 }, { _id: '2', sum: 863.93 } ],
    arr3 = [ { _id: '1', sum: 80 },  { _id: '2', sum: 220 } ],
    mainArr = [arr1, arr2, arr3];

var arrObj = [{_id:1,sum:0},{_id:2, sum:0}];

for (var i = 0; i < mainArr.length; i++) {
    for (var k = 0; k < mainArr[i].length; k++) {
        arrObj[k].sum += mainArr[i][k].sum;
    }
}

console.log(arrObj);