$ perl -le '$#{\my @array}=100;print scalar @array'
0
$ perl -le 'my @array;$#array=100;print scalar @array'
101

##</code><code>##

$ perl -le 'use strict;$#{\my @array}=100;print scalar @array'
Global symbol "@array" requires explicit package name at -e line 1.
Execution of -e aborted due to compilation errors.