十进制转化为 n 进制

decToRadixN.js

let CHARS = 'AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz0123456789-_.~!*()'; // except \'
function decToRadixN(radixChars, numLen) {
  let result = [];
  let radix = radixChars.length;
  return function cacl(dec) {
    result.unshift(dec % radix);
    if (dec >= radix) {
      dec = Math.floor(dec / radix);
      return cacl(dec, radix);
    }
    let lastNum = result.map(function(ele) {
      return radixChars[ele];
    }).join('');
    if (numLen && numLen > lastNum.length) {
      lastNum = (Array(numLen).join(CHARS[0]) + lastNum).slice(0 - numLen);
    }
    return lastNum;
  }
}

let num = decToRadixN(CHARS, 8)(490023400);
console.log(num); //AAAKOW2K