Re: Surprise: scalar(($x, $y) = split)

[JavaFan]

$ perl -e 'warn 0+(@x = split " ", "foo bar\n");'
2 at -e line 1.
$ perl -e 'warn 0+(($x, $y) = split " ", "foo bar\n");'
3 at -e line 1.
$

Note that there are *three* magical features happening. First there's the magic of the first argument; if the first argument of split is a pattern consisting of a single space, split splits on any whitespace. Which includes the newline. So, you actually have *3* fields, ("foo", "bar", "" -- the empty string following the newline), so it's the first case that's odd, not the second. It's the second magical feature that's to blame - in the absence of a limit, trailing empty fields are removed.

You wouldn't have been surprised if you had chomped your line.

[ambrus]

The other two magic might be confusing but they're not really necessary here. I can still write this and be surprised.

$ perl -we '$n = () = split ",", "one,two,three,four,five"; print "I f
+ound $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

And even if I chomp the line, there could be trailing spaces or carriage returns in the line that I expect split " " to cut off.

[hbm]

Adding to the confusion?

$ perl -e 'warn 0+(($x, $y) = split/ /, "foo bar\n");'
2 at -e line 1.
$ perl -e 'warn 0+(($x, $y) = split$", "foo bar\n");'
2 at -e line 1.