how to push 5th element from one array to another array

[Anonymous Monk]

Hi, i have an array from which i would like to put the every 5th element to another array.
how can this be done.
example myarray (1,2,3,4,5,6,7,8,sd,frd,sed,sddfsd,asecf,ssdd,myh)
i want sub array like (5,frd,myh)

[ctilmes]

my @arr = qw(1 2 3 4 5 6 7 8 sd frd sed sddfsd asecf ssdd myh);
my $i = 1;
my @arr2 = grep { $i++ % 5 == 0 } @arr;

[ikegami]

And now for something completely different

my @array = ...;
splice(@array, $_, 4) for 0..$#array/5;
print("@array\n");

[jettero]

See splice

[gmargo]

Homework? You just need a simple loop.

my @myarray = qw(1 2 3 4 5 6 7 8 sd frd sed sddfsd asecf ssdd myh);
my @fifth;

for (my $i=4; $i < scalar(@myarray); $i += 5)
{
        push(@fifth, $myarray[$i]);
}

print "fifth=".join(",",@fifth)."\n";

[merlyn]

Fifth Element? :)

[ikegami]

So

use LWP::Simple;
push @array, get('http://t0.gstatic.com/images?q=tbn:T8Bsbbf6vqMr9M:ht
+tp://www.afterellen.com/archive/ellen/blog/uploads/Milla%2520Jovovich
+-%2520Fifth%2520Element.jpg');

?

[NetWallah]

Slicy (Pretty efficient):

   my @fifth =  @arr[ map {$_*5-1} 1..$#arr+4/5 ];

Update: See gmargo's (++) correction below.

[gmargo]

Your code:

my @fifth =  @arr[ map {$_*5-1} 1..$#arr+4/5 ];

adds a fraction (4/5) to the last array index. So adding appropriate parentheses:

my @fifth =  @arr[ map {$_*5-1} 1..($#arr+4)/5 ];

seems better but it does not work for all array lengths. (It works if the length modulo 5 is 0 or 1 only.) Changing the 4 to a 1 (aka the array length) does the trick:

my @fifth =  @arr[ map {$_*5-1} 1..($#arr+1)/5 ];