# How do I fix the undefined result I keep getting from this?

So I’m doing the HackerRank superDigit challenge and even though I have the correct value for all the informal test cases, the Output box says that the result is undefined. I’m not really getting what undefined is all about or how a variable with a value returns as undefined.

```function superDigit(n, k) {

var nArr = [];

for(let i = 0; i < n.length; i++)
{
nArr.push(n[i]);
}

console.log('nArr: ' + nArr);

var nComb = 0;
for(let i = 0; i < nArr.length; i++)
{
nComb += parseInt(nArr[i]);
}
console.log('nComb: ' + nComb);

var nMult = nComb *= k;
console.log('nMult: ' + nMult);
console.log('');

if(nMult < 10)
{
return nMult;
}
else
{
superDigit(nMult.toString(),1);
}
}```

You probably want to return the `superDigit` result as well. So when calling `superDigit` recursively, add the return statement. I also cleaned up the `console.log` calls a bit so its more readable to me.

```function superDigit(n, k) {

var nArr = [];

for(let i = 0; i < n.length; i++)
{
nArr.push(n[i]);
}

var nComb = 0;
for(let i = 0; i < nArr.length; i++)
{
nComb += parseInt(nArr[i]);
}

var nMult = nComb *= k;
console.log('nMult:', nMult, 'nArr:', nArr, 'nComb:', nComb);

if(nMult < 10)
{
return nMult;
}
else
{
return superDigit(nMult.toString(),1);
}
}

document.getElementById('result').innerText = superDigit("200", 20);```
```<html>
<body>
<p id="result"></p>
</body>
</html>```