10进制浮点数转64进制

Aug 17, 2021
javascript 进制转换算法
<!DOCTYPE html>
<html>
  <head>
    <title>10进制浮点数转64进制</title>
    <script type="text/javascript">
      //进制转换，将 10 进制浮点数转换成 64 进制
      const SIGNS =
        "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-+".split(
          ""
        );

      //整数部分64进制
      function intTo64(num) {
        if (Number.isNaN(num)) {
          return "";
        }
        let result = [];
        let div = num;
        while (div > 63) {
          result.push(SIGNS[div % 64]);
          div = Math.floor(div / 64);
        }
        result.push(SIGNS[div]);
        return result.reverse().join("");
      }

      //小数部分转64进制
      function pointTo64(num) {
        if (Number.isNaN(num)) {
          return "";
        }
        //保留12位
        let precision = 12;
        let result = [];
        let multi = Number(num);
        while (result.length < precision) {
          let res = multi * 64;
          result.push(SIGNS[parseInt(res)]);
          multi = res - parseInt(res);
        }
        return result.join("");
      }

      //整个浮点数转换
      function floatTo64(num) {
        if (Number.isNaN(num)) {
          throw new Error("please input number");
        }
        let intPart = intTo64(parseInt(num));
        let pointPart = pointTo64(num - parseInt(num));
        return intPart + "." + pointPart;
      }

      console.log(floatTo64(22.66));
    </script>
  </head>
  <body></body>
</html>