Question

I’m doing some JavaScript self-study, trying to check if n is anything other than a number in the third if of the factorial function, but I can’t get it to work. Any help would be appreciated

var factorial = function(n) {
    // Update so that all tests pass
    if (n > 20) {
        return undefined;
    }
    if (n === 1) {
        return 1;
    }
    if(isNan(n)){
        return undefined;
    }
    return n * factorial(n-1);
};

Answer 1

isNaN() has two ​​​capital Ns.