I'm trying to remove all negative integers from the following array :

```
$array = array([-122,121,-124,124,-121,122,-122,124,-121,124,-122,125,-121,121,-123,122,-124,120]);

```

I've tried the following, it's not working as I don't really understand how `array_filter` works :

```
function positive($var) {
  if ($var >= 0) {
    return $var;
  }
}

print_r(array_filter($array, positive($var)));

```

How would I send each value to the `positive` function? Or is there a better way of doing this? `array_walk` or `array_map` maybe?