code: function lengthOfNumber(number) {
          if (isNumber(number)) {
              var length_1 = 0;
              while (number > 0) {
                  length_1++;
                  number = backIntegerOfNumber(number / 10);
              }
              return length_1;
          }
          else {
              return 0;
          }
      }
docs: Example: number = 12345; return = 5