Subtract the Product and Sum of Digits of an Integer

MultiplicationAndSumofDigits_optimal.js

var subtractProductAndSum = function(n) {
    if (n / 10 == 0)
        return 0;
    let mul = 1, sum = 0;
    while( n != 0) {
        mul *= n % 10;
        sum += n % 10;
        n = Math.trunc(n / 10);
    }
return mul - sum;
};

This was the most useful problem