You're asking the wrong question, which is the problem. You're asking "How do I simultaneously declare a variable and use it within a loop to sum a list?" You really want to ask "How do I sum the values in a loop and assign the result to a variable?"
use List::Util qw( reduce );
my $t = reduce { $a + $b } @list;
# Or ...
use List::Util qw( sum );
my $t = sum @list;
Being right, does not endow the right to be rude; politeness costs nothing.
Being unknowing, is not the same as being stupid.
Expressing a contrary opinion, whether to the individual or the group, is more often a sign of deeper thought than of cantankerous belligerence.
Do not mistake your goals as the only goals; your opinion as the only opinion; your confidence as correctness. Saying you know better is not the same as explaining you know better.
