Question

Just wishing to quickly verify this. It is different from my immediate experience from other languages whereby an array must first be declared before it can be filled with values.

Answer 1

Yes, PHP will automatically create an array given any of the following

$foo[] = $bar;
$foo[1] = $bar;
$foo['bar'] = $bar;

// and of course
$foo = array();

// and soon to pass
$foo = [1, 2, 3];