js计算多个数的最大公约数和最小公倍数

    function fn (a, b) {
      if (b===0) {
        return a
      } else {
        return fn4(b, a%b);
      }
    }

    function fn2 () {
      let arr = Array.from(arguments);
      if (arr.length < 1) return;
      while (arr.length > 1) arr.splice(0,2,fn4(arr[0],arr[1]));
      return arr[0];
    }

    function fn3 (a, b) {
      return a * b / fn(a, b);
    }

    function fn4 () {
      let arr = Array.from(arguments);
      while (arr.length > 1) arr.splice(0,2,fn42(arr[0],arr[1]));
      return arr[0];
    }