getElementsByTagName() does not return array

[MaximMoinat]

If you try to get all the anchors like this, then by default one (the last) element is returned:
$anchors = $soup->getElementsByTagName('a');
The following does give me all the elements:
$anchors = $soup->getElementsByTagName('a', null);

The idx value defaults to -1. Is this on purpose?

[sunra]

@MaximMoinat I think it is old php versions legacy. It in no particular purpose now.