$ perl -e " print qq!($_)\n! for split /,/, q!,1,2,3!"
()
(1)
(2)
(3)

$ perl -e " print qq!($_)\n! for split /,/, q!,,,,1,2,3!"
()
()
()
()
(1)
(2)
(3)

$ perl -e " print qq!($_)\n! for split /(,)/, q!,,,,1,2,3!"
()
(,)
()
(,)
()
(,)
()
(,)
(1)
(,)
(2)
(,)
(3)

##</code><code>##

$ perl -e " print qq!($_)\n! for split /,/, q!5,,,!"
(5)

$ perl -e " print qq!($_)\n! for split /(,)/, q!5,,,!"
(5)
(,)
()
(,)
()
(,)