my $a = [];
$a->[$_] = $_ for 0..999;
$#$a = 1; # frees up  approx 16000 bytes
undef @$a; # frees a further 4000 bytes
undef $a;  # frees a further 52 bytes

[download]
Note that this frees memory to the perl interpter, not to the OS. ie perl can reuse that memory when creating further data, but other processes can't

update: to clarify: just doing the undef $a on its own would free up all 20052 bytes too.

Dave.

In reply to Re^3: memory "release" with $#=-1 by dave_the_m
in thread memory "release" with $#=-1 by ISAI student

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