题目描述

请返回参数数字的千分位分隔符字符串。

测试用例

用例1：

• 输入：_comma(12300)
• 输出：'12,300'

代码实现

function _comma(number) {
  // 补全代码
  let numberStr = number.toString();
  let len = numberStr.length;
  if (len < 4) {
    return number;
  }
  let cur = len - 3;
  let res = "";
  let temp = "";
  let a = 0;
  while (cur > 0) {
    if (a == 0) {
      res = numberStr.slice(0, cur) + "," + numberStr.slice(cur);
      cur = cur - 3;
      temp = res;
      a++;
    } else {
      res = temp.slice(0, cur) + "," + temp.slice(cur);
      cur -= 3;
      temp = res;
    }
  }
  return res;
}
// len = 7 cur = 4
// cur = 1
const res = _comma(1234567);
console.log("res: ", res);
// res:  1,234,567