I have an array of strings say whose length can be anywhere from 1 to 20. I need to join the 1st 3 elements of array into a string. I used.
@a = ("Hello","world","welcome");
$b = join(":",@a[0..2])
This produces desired output Hello:World:welcome
But When the length of the array is less than 3 say @a = ("hello","wolrd")
I get Hello:world: as output. If I have 1 variable I get Hello:: as the output.
I want to restrict joining based on the array's length. Is there any way out to do this?
With List::Util 1.50 or newer you get the head function which is nice for this sort of thing, as it will only return up to the number of elements in the list.
use strict;
use warnings;
use List::Util 1.50 'head';
my @array = ('hello', 'world');
my $joined = join ':', head 3, @array; # hello:world
The splice function can serve as a poor-man's head/tail, but it requires an array specifically and will remove the returned elements from that array.
use strict;
use warnings;
my @array = ('hello', 'world');
my $joined = join ':', splice @array, 0, 3; # hello:world
# @array is now empty
Can also check the array size and join what you want, or the whole array
my $joined = join ':', (@ary > 3 ? @ary[0..2] : @ary);
You need a grep to filter out values that are undef.
my $b = join(":", grep defined, @a[0..2]);
Note that this will allow values with the empty string q{}.