a,b,c,d
e,f,g,h
i,j,k,l

@arr1 before the chomp should like like above when printed out.

Why would you expect that?

>perl -wMstrict -le
"my $s = qq{a,b,c,d\ne,f,g,h\ni,j,k,l};
 printf qq{$s};
 printf qq{\n};
 ;;
 my @ra = split /\n/, $s;
 printf qq{@ra};
 printf qq{\n};
 ;;
 chomp @ra;
 printf qq{@ra};
 printf qq{\n};
"
a,b,c,d
e,f,g,h
i,j,k,l
a,b,c,d e,f,g,h i,j,k,l
a,b,c,d e,f,g,h i,j,k,l
[download]