Finding the Most Common Anything
Problem
You have an aggregate data structure, such as an array or a hash. You want to know how often each element in the array (or key or value in the hash) occurs. For instance, if your array contains web server transactions, you might want to find the most commonly requested file. If your hash maps usernames to number of logins, you want to find the most common number of logins.
Solution
Use a hash to count how many times each element, key, or value appears:
%count = (); foreach $element (@ARRAY) { $count{$element}++; }
Discussion
Any time you want to count how often different things appear, you
should probably be using a hash. The foreach
adds
one to $count{$element}
for every occurrence of
$element
.
See Also
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