比较两个数组的值，如果值被删除而不是相加，则仅返回差值

function compareArrays(arr1, arr2) {
  arr1.sort();
  arr2.sort();

  let diff = [];

  let i = 0;
  let j = 0;

  while (i < arr1.length && j < arr2.length) {
    if (arr1[i] === arr2[j]) {
      i++;
      j++;
    } else if (arr1[i] < arr2[j]) {
      diff.push(arr1[i]);
      i++;
    } else {
      diff.push(arr2[j]);
      j++;
    }
  }

  while (i < arr1.length) {
    diff.push(arr1[i]);
    i++;
  }

  while (j < arr2.length) {
    diff.push(arr2[j]);
    j++;
  }

  return diff;
}

const arr1 = [1, 2, 3, 4, 5];
const arr2 = [2, 3, 5, 6];

const diffArray = compareArrays(arr1, arr2);
console.log(diffArray);