Category Archives: Idiomatic Perl

Don’t use auto-dereferencing with each or keys

Perl 5.14 added an auto-dereferencing features to the hash and array operators, and I wrote about those in Use array references with the array operators. I’ve never particularly liked that feature, but I don’t have to like everything. Additionally, Perl 5.12 expanded the job of keys and values to also work on arrays.

Know split’s special cases

Perl’s split has some special cases and some perhaps surprising cases. The empty pattern, zero width match, the special argument ‘ ‘, and the /^/ act differently than you might expect from the general rule. The empty pattern, // The empty pattern is a special case that’s designed to give you a list of characters. […]

Count the number of times a character occurs in a string

This Item isn’t really about counting characters in a string, but we thought we’d expand on an Item in the original Effective Perl blog that Joseph set up to support the first edition of Effective Perl Programming. He had an Item titled “Counting the Number of Times a Character Occurs in a String”. We won’t […]

Make exclusive flip-flop operators

In Respect the global state of the flip flop operator, you saw some examples of the .. scalar operator. The flip-flop operator returns false until its lefthand side is true. Once the lefthand side is true, the flip-flop operator returns true until its righthand side is true. Once the righthand side is true, the flip […]

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