length is for getting string lengths. To get the number of elements, simply use the array in scalar context:

my $elems = @$array_ref;
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moritz is right. You can force an array into a scalar context using scalar(), but that is seldom necessary. For example, $asdad was assigned value 1 because the arguments to length() are in scalar context, so it is as though you had said length("3"), which is 1. If there had been 10 items in the array, you'd have a two-digit length, and $asdad would have been assigned 2.

Assuming, I don't know number of elements in @sss

my $number_in_array_sss  = @sss;

print scalar(@sss). " ". $num\n";
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#!/usr/bin/perl -w
use strict;
use Data::Dumper;

my @sss = ("1","3","4");
my $reee = [];

foreach my $entry (@sss)
{
    push (@$reee, $entry);
}

# this is to show various uses of scalar() and that
# the dot (concatenation) operator forces scalar context

print "\$ree has ",scalar(@$reee)," elements\n";
print "\$ree has ".@$reee." elements\n";
print ''.@$reee." elements\n";
print "each element is: @$reee \n";
print Dumper \$reee;

#PRINTS:
#$ree has 3 elements
#$ree has 3 elements
#3 elements
#each element is: 1 3 4 
#$VAR1 = \[
#            '1',
#            '3',
#            '4'
#          ];

# To accomplish the above is only one Perl statement!!

# No "foreach" or "for" loop is needed, 3 lines of code
# becomes one line of code. I do not count blank lines
# or lines with just braces "{}" as "lines of code".

my @aaa = (1,5,7);   # like @sss, repeated for clarity
                     #   and using different numbers.
my $bbb = [@aaa];    # this means: 
                     #   allocate some memory and assign its
                     #   reference to $bbb.
                     # The array, @aaa is copied to that
                     #   memory referenced by $bbb. 
print Dumper \$bbb;

#prints
#$VAR1 = \[
#            1,
#            5,
#            7
#          ];
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Finding number of elements in an array from array reference, you can get it by different ways like,

1. As moritz said, use the array in scalar context like

2. or, you can use scalar like,

3. or, you can use int like

... or, you can use scalar...

Why? Scalar assignment always imposes scalar context.

... you can use int like...

Why? Scalar assignment always imposes scalar context, and an array in scalar context always evaluates to an integer.

Make it easy on yourself!

Why? Scalar assignment always imposes scalar context.

Perhaps the OP didn't want to do an assignment. Contrast

  @a = ( 42 );
  printf("%d\n", @a);         # prints 42
  printf("%d\n", scalar(@a)); # prints 1
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I find it is seldom necessary to use scalar(), since I'm more likely to do assignment or conditional testing, where scalar context is implied. But scalar() has its place when the default is list context.