Re^2: Perl Objects, Internal Representation -- How??

What about hash keys- are they duplicated for each object of the same type?
Yes.

Er, no. Hash keys are generally shared across all hashes, as the following shows. Using the same key for lots of objects uses less memory than a different key for each one:

$ perl588 -e 'push @f,  bless { "foo$_",0 } for 100000..999999; system
+ "ps -flp $$"'
F S UID        PID  PPID  C PRI  NI ADDR SZ WCHAN  STIME TTY          
+TIME CMD
0 S davem     6040 17980 81  85   0 - 43121 wait   19:05 pts/2    00:0
+0:04 perl5
$ perl588 -e 'push @f,  bless { "foo999999",0 } for 100000..999999; sy
+stem "ps -flp $$"'
F S UID        PID  PPID  C PRI  NI ADDR SZ WCHAN  STIME TTY          
+TIME CMD
0 S davem     6045 17980 96  85   0 - 34173 wait   19:06 pts/2    00:0
+0:03 perl5
$
[download]

Dave.

Comment on Re^2: Perl Objects, Internal Representation -- How?? Download Code

Replies are listed 'Best First'.
Re^3: Perl Objects, Internal Representation -- How?? by perrin (Chancellor) on Sep 15, 2006 at 18:30 UTC
Good point -- the actual keys of hashes are shared to reduce memory needed. There's a good explanation in PerlGuts Illustrated. This is just standard hash behavior though, not at all related to them being used as objects.	[reply]