As pileswasp pointed out, you can preallocate your hash by assigning to keys, similar to preallocating an array by assigning to $#array.

Most of the time, of course, you'll just let Perl worry about the number of buckets. Here's how that works...

When you add a new key to the hash, perl checks whether there are too many keys for the number of buckets. If that's the case, perl allocates a bunch more buckets. Then, perl goes through the whole hash, calls the hash function for each key, and figures out where it belongs in the newly-resized hash.

You're probably thinking that resizing the hash and reinserting all the elements is slow; you're absolutely right. When perl has to resize a hash, it doubles the number of buckets, which keeps it from having to resize your hashes too often.

In reply to Re: Re: Re: Re: Re: print scalar %hash... erm by chipmunk
in thread print scalar %hash... erm by pileswasp

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