Basically
returns the value of $h{$_} then increments it. If there is no value at $h{$_} perl will initialise it to zero.
So, for each value that $_ may be, the first evaluation is zero and subsequent evaluations are non-zero. The exclamation point negates the values into True if zero, False if non-zero.
Does that help?
Andrew
These 2 Users Gave Thanks to apmcd47 For This Post:
Hi,
When using sort on an associative array:
foreach $key (sort(keys(%opalfabet))){
$value = $opalfabet{$key};
$result .= $value;
}
How does it handle double values?
It seems to me that it removes them, is that true? If so, is there a way to get... (2 Replies)
hi all
i was going through some perl code i came across this line and i am not getting what is exactly going on ..
$$this{localtion} = GetName->GetVarName("EXE_DIR") ;
what is the red part doing in above code (2 Replies)
Hi Everyone,
I have:
my @No=qw(032106 032630 0380 034010 035110 0354801111);
my $str_No=join(';', @No);
I have a string $strA="03263033", so in order to determine this $strA area code matches with @No, I can do:
if ( (rindex($str_No,substr($strA,0,5))))== -1) ) {
print "Not... (1 Reply)
How is it possible to sort different nummeric values within an Array. But i don`t want the highest or the lowest. I need the most frequently occurring value.
For examble:
My Array has to following values = (200 404 404 500 404 404 404 200 404)
The result should be 404
The values are... (3 Replies)
Hi All,
I have an array in perl as @match = (201001,201002,201001,201002);
I am trying to sort this array as
@match = sort(@match);
print "@match";
I dont see the output sorted any answers
I also tried another way, but still the results are not sorted
foreach my $match (sort { $a... (2 Replies)
Hi,
i have a txtfile with the format <Nr>tab<word>tab<other stuff>new line and i want to sort the <word>-colum with a perl script.
My textfile:
<Nr>tab<word>tab<other stuff>new line
6807 die ART.Acc.Sg.Fem
6426 der ART.Gen.Sg.Fem
2 die ART.Nom.Sg.Fem
87 auf APPR.--
486 nicht PTKNEG.--... (1 Reply)
Hi all,
Not sure if this should be in the programming forum, but I believe it will get more response under the Shell Programming and Scripting FORUM.
Am trying to write a customized df script in Perl and need some help with regards to using arrays and file handlers.
At the moment am... (3 Replies)
I am using this line of perl code to change the file format and remove ^M at the end of each line in files:
perl -i -pe's/\r$//;' <name of file here>
Can you explain to me what this code does, and translate it into bash/awk/sed? (2 Replies)
@sorted = sort { $a <=> $b } @unsorted;
I am having hard time understanding how this works? I know the output but interested to know the working.
Thanks in advance. (2 Replies)
Discussion started by: Tanu
2 Replies
LEARN ABOUT DEBIAN
devel::refcount
Devel::Refcount(3pm) User Contributed Perl Documentation Devel::Refcount(3pm)NAME
"Devel::Refcount" - obtain the REFCNT value of a referent
SYNOPSIS
use Devel::Refcount qw( refcount );
my $anon = [];
print "Anon ARRAY $anon has " . refcount($anon) . " reference
";
my $otherref = $anon;
print "Anon ARRAY $anon now has " . refcount($anon) . " references
";
DESCRIPTION
This module provides a single function which obtains the reference count of the object being pointed to by the passed reference value.
FUNCTIONS
$count = refcount($ref)
Returns the reference count of the object being pointed to by $ref.
COMPARISON WITH SvREFCNT
This function differs from "Devel::Peek::SvREFCNT" in that SvREFCNT() gives the reference count of the SV object itself that it is passed,
whereas refcount() gives the count of the object being pointed to. This allows it to give the count of any referent (i.e. ARRAY, HASH,
CODE, GLOB and Regexp types) as well.
Consider the following example program:
use Devel::Peek qw( SvREFCNT );
use Devel::Refcount qw( refcount );
sub printcount
{
my $name = shift;
printf "%30s has SvREFCNT=%d, refcount=%d
",
$name, SvREFCNT($_[0]), refcount($_[0]);
}
my $var = [];
printcount 'Initially, $var', $var;
my $othervar = $var;
printcount 'Before CODE ref, $var', $var;
printcount '$othervar', $othervar;
my $code = sub { undef $var };
printcount 'After CODE ref, $var', $var;
printcount '$othervar', $othervar;
This produces the output
Initially, $var has SvREFCNT=1, refcount=1
Before CODE ref, $var has SvREFCNT=1, refcount=2
$othervar has SvREFCNT=1, refcount=2
After CODE ref, $var has SvREFCNT=2, refcount=2
$othervar has SvREFCNT=1, refcount=2
Here, we see that SvREFCNT() counts the number of references to the SV object passed in as the scalar value - the $var or $othervar
respectively, whereas refcount() counts the number of reference values that point to the referent object - the anonymous ARRAY in this
case.
Before the CODE reference is constructed, both $var and $othervar have SvREFCNT() of 1, as they exist only in the current lexical pad. The
anonymous ARRAY has a refcount() of 2, because both $var and $othervar store a reference to it.
After the CODE reference is constructed, the $var variable now has an SvREFCNT() of 2, because it also appears in the lexical pad for the
new anonymous CODE block.
PURE-PERL FALLBACK
An XS implementation of this function is provided, and is used by default. If the XS library cannot be loaded, a fallback implementation in
pure perl using the "B" module is used instead. This will behave identically, but is much slower.
Rate pp xs
pp 225985/s -- -66%
xs 669570/s 196% --
SEE ALSO
o Test::Refcount - assert reference counts on objects
AUTHOR
Paul Evans <leonerd@leonerd.org.uk>
perl v5.14.2 2011-11-15 Devel::Refcount(3pm)