http://www.perlmonks.org?node_id=705515


in reply to Re^3: Avoiding silly programming mistakes
in thread Avoiding silly programming mistakes

If you even declare a variable, it would be nonsensical to warn when you assign to it. It's more the other way round:
if (my $x) { ... }

(variable declaration in a conditional without assignment) could actually warn, because it will never be true. (But perl intentionally doesn't have such warnings, some people like stuff like if (0) { ... }).