JavaScript 正则表达式查找最长连续子串长度

function maxLenStr(str){
  var len = 0, max_len = 0;
  var reg = new RegExp("(.)\\1{1,}","g");
  var res = reg.exec(str);
  while(res != null){
    len = res[0].length;
    if(max_len < len){
      max_len = len;
    }
    res = reg.exec(str)
  }
  return max_len;
}

var str = '#param1#abcdef#param2#hjklllj#param3#7878'
var count = str.match(/param\d*/g)
console.log(count) ／／ ["param1", "param2", "param3"]