Items in Container

const getItems = (str, startIndices, endIndices) => {
  let count = 0;
  const arr = Array(str.length);
  arr[0] = 0;
  for (let i = 1; i < str.length; i++) {
    if (str[i] === '*') {
      count++;
      arr[i] = arr[i - 1];
    } else {
      arr[i] = count;
    }
  }
  const ret = Array(startIndices.length);
  for (let i = 0; i < startIndices.length; i++) {
    ret[i] = arr[endIndices[i] - 1] - arr[startIndices[i] - 1];
  }
  return ret;
}

console.log(getItems('|**|*|*', [1, 1], [5, 6])); // [2,3]

Demo