如何使用js使用RegExp对字符串中相同字符组成的子串进行计数

function countSubstring(str) {
  var regex = /(.)\1+/g;
  var result = {};
  var match;

  while ((match = regex.exec(str)) !== null) {
    var substring = match[0];
    var count = substring.length / match[1].length;
    result[substring] = count;
  }

  return result;
}

var str = "aabbbccdd";
var counts = countSubstring(str);
console.log(counts);

{
  "aa": 1,
  "bbb": 1,
  "cc": 1,
  "dd": 1
}