KEY: 0, VAL: a
KEY: 1, VAL: b
KEY: 2, VAL: c
<HR> $c= $a[0];
<HR> $d[0]= $a[0];
KEY: 0, VAL: a
count(): 1
<HR> $e[]= $a[0];
KEY: 0, VAL: a
count(): 1
<HR> append to $f[0] $f[1] $f[2], $f += $a;
KEY: 0, VAL: e
KEY: 1, VAL: f
KEY: 2, VAL: g
count(): 3