Is the 'my $x if 0' trick usable for static variable creation for Perls before 5.10?

Question

In Perl before 5.10 there is no \"state\" declaration.

I\'ve come across an example of creating static variables in these Perls: my $x if 0. The i

Answer 1

I've always used scoping braces to create static variables.

add() for 1..2;       # Append to existing.
add('foo', 'bar');    # Re-initialize if args are passed.
add() for 1..2;       # Append to existing.
{
    my @arr;
    sub add {
        @arr = @_ if @_;
        push @arr, '+';
        print @arr, "\n";
    }
}