Let's say I have two arrays such as:

```
$arrayOne = array(1, 2, 3, 4, 5, 6, 7, 8);
$arrayTwo = array(2, 4, 6);

```

How do I get an `$arrayThree`such that:

```
$arrayThree = array(1, 3, 5, 7, 8);

```