What would be the difference here in using || and && … why my code works but doesnt pass the test

cheers

**Your code so far**

```
// Setup
function abTest(a, b) {
// Only change code below this line
if (a && b < 0) {
return;
}
// 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:**

Your Browser User Agent is: `Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.186 Safari/537.36`

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**Link to the challenge:**

https://www.freecodecamp.org/challenges/return-early-pattern-for-functions