**Tell us what’s happening:**

When I take the return undefined out of the if/else, it returns undefined. Placing it in an if/else returns NaN, are there any ideas why?

**Your code so far**

```
// Setup
function abTest(a, b) {
// Only change code below this line
if (abTest < 0) {
return undefined;
} else {
// Only change code above this line
return Math.round(Math.pow(Math.sqrt(a) + Math.sqrt(b), 2));
}
}
// Change values below to test your code
abTest(2,2);
```

**Your browser information:**

User Agent is: `Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36`

.

**Link to the challenge:**

https://learn.freecodecamp.org/javascript-algorithms-and-data-structures/basic-javascript/return-early-pattern-for-functions/