小数千位符实现小数的千位符：

实现小数的千位符：
<!DOCTYPE html>
<html lang="“cn”">
  <head>
    <meta charset="“utf-8”" />
    <title>title</title>
    <style></style>
    <script>
      function thousandBitSeparator(num) {
        return (
          num &&
          (num.toString().indexOf(".") != -1
            ? num.toString().replace(/(\d)(?=(\d{3})+\.)/g, function ($0, $1) {
                return $1 + ",";
              })
            : num.toString().replace(/(\d)(?=(\d{3}))/g, function ($0, $1) {
                return $1 + ",";
              }))
        );
      }

      const formatNumber = (num, n = 2) => {
        try {
          if (typeof num !== "number" && !num) return "-";
          num = (typeof num === "number" ? num : +num).toFixed(
            Math.max(0, ~~n)
          );
          const nums = `${num}`.split(".");
          if (nums[1]) {
            const left = nums[0].replace(/\d(?=(\d{3})+$)/g, "$&,");
            const right = nums[1].replace(/(?<=^(\d{3})+)\d/g, ",$&");
            return `${left}.${right}`;
          } else {
            return num.replace(/\d(?=(\d{3})+$)/g, "$&,");
          }
        } catch {
          return "-";
        }
      };

      const a = formatNumber(1234567890.123456789123, 12);
      console.log(a);
      console.log(typeof a);
    </script>
  </head>
  <body>
    2222222
  </body>
</html>
小数 千位符

小数千位符
