Re^3: regexp list return 5.6 vs 5.8

Really, I too was surprised. Changing sub test to

sub test {
    my @rv = $_[0] =~ /^([0-9]+)$/;
    print "<<@rv>>\n";
    return @rv[ 0 .. $#rv ];
}
[download]

produced

<<>>
[[]
<<>>
[]
<<123>>
[123]
<<123>>
[123]
[download]

changing sub test to

sub test {
    my @rv = $_[0] =~ /^([0-9]+)$/;
    print "<<@rv>>\n";
    return wantarray? @rv: $rv[-1];
}
[download]

produces

michael$ perl t.pl
<<>>
Use of uninitialized value in print at t.pl line 5.
[]
<<>>
[]
<<123>>
[123]
<<123>>
[123]
[download]

Note the warning. (And I suspect there are some monks who are now saying I told you so;-)

Comment on Re^3: regexp list return 5.6 vs 5.8 Select or Download Code

Replies are listed 'Best First'.
Re^4: regexp list return 5.6 vs 5.8 by Sixtease (Friar) on Jan 24, 2008 at 09:50 UTC
Wow, so the `[[]` was not a typo? I thought it was. I still don't understand how it could have got there! What does it print when you use different delimiters? (like `print "{", scalar(test('abc')), "}";`) use strict; use warnings; print "Just Another Perl Hacker\n";	[reply] [d/l] [select]
Re^5: regexp list return 5.6 vs 5.8 by hipowls (Curate) on Jan 24, 2008 at 10:21 UTC
Strange indeed. `michael$ perl t.pl {{} {} {123} {123}` [download]	[reply] [d/l]
Re^6: regexp list return 5.6 vs 5.8 by johngg (Canon) on Jan 25, 2008 at 10:15 UTC
Putting the call inside a `@{[ ... ]}` construct does something different. `print "[@{ [ scalar test('abc') ] }]\n"; print "[", scalar test('abc'), "]\n\n"; print "[@{ [ test('abc') ] }]\n"; print "[", test('abc'), "]\n\n"; print "[@{ [ scalar test('123') ] }]\n"; print "[", scalar test('123'), "]\n\n"; print "[@{ [ test('123') ] }]\n"; print "[", test('123'), "]\n"; sub test { my @rv = $_[0] =~ /^([0-9]+)$/; return @rv[ 0 .. $#rv ]; }` [download] produces `[ ] [[] [] [] [123] [123] [123] [123]` [download] Running 5.8.4 on Solaris 9. Cheers, JohnGG	[reply] [d/l] [select]