P:\test>perl -MO=Deparse -e"@a = 1,2,3,4,5; print @a"
@a = 1, '???', '???', '???', '???';
print @a;
-e syntax OK

P:\test>perl -e"@a = 1,2,3,4,5; print @a"
1


P:\test>perl -MO=Deparse -e"@a = (1,2,3,4,5); print @a"
@a = (1, 2, 3, 4, 5);
print @a;
-e syntax OK

P:\test>perl -e"@a = (1,2,3,4,5); print @a"
12345