Number of array elements: 4.<br><pre>Array
(
    [0] => Audi
    [1] => BMW
    [2] => Renault
    [3] => Nissan
)
</pre>Audi is part of our brands.<br>Mercedes is not part of our brands.<br>Number of array elements: 5.<br><pre>Array
(
    [0] => Audi
    [1] => BMW
    [2] => Renault
    [3] => Nissan
    [4] => Hyundai
)
</pre>Number of array elements: 4.<br><pre>Array
(
    [0] => Audi
    [1] => BMW
    [2] => Renault
    [4] => Hyundai
)
</pre>Nissan ** Hyundai<br><pre>Array
(
    [0] => Audi
    [1] => BMW
    [2] => Renault
    [4] => Hyundai
    [3] => Nissan
)
</pre>Number of array elements: 4.<br><pre>Array
(
    [0] => Audi
    [1] => BMW
    [2] => Renault
    [3] => Nissan
)
</pre>Number of array elements: 5.<br><pre>Array
(
    [0] => Audi
    [1] => BMW
    [2] => Renault
    [3] => Nissan
    [4] => VW
)
</pre>The third brand is Renault.<br><pre>Array
(
    [0] => LAM
)
</pre>'2' is not in $numbers1<br>'2' is in $numbers1<br><pre>Array
(
    [0] => 1
    [1] => 2
    [2] => 3
    [3] => 4
    [4] => 1
    [5] => 5
    [6] => 6
    [7] => 7
)
</pre><br>The result of the magic formula is 2.5