js 取接近x 倍数的整数

    function closestMultiple(n, x)

    {

           if (x > n)

            return x;

        n = n + parseInt(x / 2, 10);

        n = n - (n % x);

        return n;

    }

测试

closestMultiple(6,5)
5
closestMultiple(19,5)
20
closestMultiple(19,100)
100
closestMultiple(199,100)
200