$ perl -we '$n = () = split ",", "one,two,three,four,five"; print "I found $n comma-separated words\n"'
I found 1 comma-separated words
$ perl -we '$n = ($x) = split ",", "one,two,three,four,five"; print "I found $n comma-separated words, the first of which is $x\n"'
I found 2 comma-separated words, the first of which is one