From a data point of view, none.

From a reader / programmer point of view, in one case you have explicitly empty elements, in the other it's implied and the focus is on declaration of the variable and its scoping. You could for example use the first syntax as a reminder that your container might still be empty by the end, and the second when you are just defining the variable to give a specific scope, but the data has to be found somewhere else.

In reply to Re: initialize arrays and hashes by Eily
in thread initialize arrays and hashes by Anonymous Monk

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