Page History

...

Some functions do not define what they return in list or scalar context. For instance, according to the {[perlfunc}} manpage, the sort() function "sorts the LIST and returns the sorted list value. In scalar context, the behavior of 'sort()' is undefined."

Noncompliant Code Example (sort())

...

sub ret {
  my $list = shift;
  my @list = @{$list};
  # ...
  return sort @list;
}

my @list = ( "foo", "bar", "baz");
my $result = ret @list;

...

sub ret {
  my $list = shift;
  my @list = @{$list};
  # ...
  return sort @list;
}

my @list = ( "foo", "bar", "baz");
my @result = ret @list;

In this case, the @result array will contain the list { {{ "bar", "baz", "foo"}}}.

Risk Assessment

Using an unspecified value can lead to erratic program behavior.

Automated Detection

Bibliography

...

...

[

...

Conway

...

2005]
[Manpages]	perlfunc

 

...

Image Added Image Added Image Added|AA. Bibliography#Conway 2005]\] \[[Manpages|AA. Bibliography#Manpages]\] [perlfunc|http://perldoc.perl.org/perlfunc.html]EXP11-C. Do not apply operators expecting one type to data of an incompatible type      03. Expressions (EXP)      EXP13-C. Treat relational and equality operators as if they were nonassociative