It's not at all hard to see it – an example is not necessary. The perldoc quoted in the first reply says everything: the trick works by means of join(), such that it would have been far better if the feature had not been a part of the language and programmers had to type a few extra letters into their 300-baud teletypes. If your data contains the separator-character, the code breaks. Whereas, if you (today) use hash-of-hashes and auto-vivification, you can quickly construct real multi-dimensional data structures without concern for what the hash-key values might be, and the code is no more cumbersome. Some of the "older" ideas in Perl were really good ones. But this is not one of them.

In reply to Re^3: Hash key composition with a comma? by Anonymous Monk
in thread Hash key composition with a comma? by mpersico

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