编辑代码

let str = "jiejoeyertgt4757854yt7834t347t3487iuhiuwehuwe";
var newArr = [];
for (i = 0; i < str.length; i++) {
  newArr.push(str[i])
}
//var arr2 = newArr.map(Number)
function group(array, subGroupLength) {
    let index = 0;
    let newArray = [];
    while(index < array.length) {
        newArray.push(array.slice(index, index += subGroupLength));
    }
    return newArray;
}
let arr = newArr;
let groupArr = group(arr, 3);
//console.log(groupArr)
for(let i = 0; i < groupArr.length; i++) {
        for(let j = 0;j < groupArr[i].length;j++){
            console.log(groupArr[i][j])
        }
      }