Add the corresponding subscripts of multiple arrays in the object

Problem description

There are n An array of the same length （ The length is m）, take n Add the same subscripts of arrays , The length of the returned array is m

js Code implementation

let obj = {
    
  arr1: [1, 2, 3, 4],
  arr2: [3, 4, 5, 6],
  arr3: [2, 3, 4, 5],
  arr4: [1, 1, 1, 1],
};

function getNewArray(obj) {
    
  const arr = Object.values(obj);// Take out all the attribute values in the object and put them into the array （ Easy to use array api）
  let res = [];
  for (let i = 0; i < arr[0].length; i++) {
    
    arr.forEach((item) => {
    // Traverse the newly obtained array 
      if (res[i] == undefined) {
    
        res[i] = 0;// When there is no value at a certain position in the array , Set this position to 0（ Otherwise, the result is [NaN,NaN]）
      }
      res[i] += item[i];// Add the subscripts corresponding to each item 
    });
  }
  return res;
}
console.log(getNewArray(obj));