Perl hash size FAQ: How do I get the size of a hash in Perl?
Short answer: To get the size of a Perl hash (the Perl hash size), use the Perl "keys" function, and assign it to a scalar value, like this:
$size = keys %my_hash;
The variable $size will now contain the number of keys in your Perl hash, which is the size of the hash, i.e., the total number of key/value pairs in the hash.
Perl hash size - a complete example
As a more thorough Perl hash size answer, let's build a complete Perl script. First, we define a Perl hash named %prices, like this:
# create our perl hash
$prices{"pizza"} = 12.00;
$prices{"coke"} = 1.25;
$prices{"sandwich"} = 3.00;
Now we can get the size of our Perl hash, like this:
$size = keys %prices;
Putting this all together in a Perl script, and printing the Perl hash size at the end of the script, we have this:
#!/usr/bin/perl
# a "perl hash size" demo script
# devdaily.com
# create our perl hash
$prices{'pizza'} = 12.00;
$prices{'coke'} = 1.25;
$prices{'sandwich'} = 3.00;
# get the hash size
$size = keys %prices;
# print the hash size
print "The hash contains $size elements.\n";
which gives us this output:
The hash contains 3 elements.
More Perl hash tutorials
I hope you found this Perl hash size tutorial helpful. We have many more Perl hash tutorials on this site, including the following:
Getting started Perl hash tutorials:
- Perl hash introduction/tutorial
- Perl foreach and while: how to loop over the elements in a Perl hash
- Perl hash add - How to add an element to a Perl hash
- How to print each element in a Perl hash
More advanced Perl hash tutorials:
The hash in Perl - hash sorting tutorials:
- Perl hash sorting - Sort a Perl hash by the hash key
- Perl hash sorting - Sort a Perl hash by the hash value
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