3rd Edition of the Camel, first paragraph of chapter 4, p.111 discusses this.
Perl does not force you to program in any particular style, but most experienced programmers have made enough mistakes to know that initialising variables, like use warnings and use strict, are a Good Thing.
Strangely I can't find a direct 'Best Practice' to initialize variables in TheDamian's book.

In reply to Re^2: Debugging "Use of uninitialized value" warnings. by cdarke
in thread Debugging "Use of uninitialized value" warnings. by cwry

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