Perl: array splitting and complex merging

Question

I have the following string A B C D E F G H I J. I want to make an array out of it, so I use this

my @string = split/(\W)/, $text;

It works ok, and I get an array of 20 lines looking like this:

A

B

C

D

...

Now, I want to split this array in a given number of pieces (let's say 4 in this case), thus resulting I imagine in 4 smaller arrays of 5 lines each, looking like this @1 = A, ,B, ,C , @2 = ,D, ,E,, @3 = F, ,G, ,H and @4 = ,I, ,J,. Finally, I want to interleave these 4 arrays in order to get an output array in which I first have the first line of each array, the the second line of each array, and so on... the final thing looking like this :

A

F


D

I
B

G


E

J
C

H

How to achieve this?

Answer 1

1. To make a slice of an array in Perl:

   my @oldArray = (a, ,b, ,c, ,d, ,e, ,f, ,g, h, ,i, ,j, );
   
   my @newArray1 = @oldArray[elemIndex1,elemIndex2,elemIndexN];
   

   OR

   my @newArray1 = @oldArray[firstElemIndex..lastElemIndex]
   

   Where elemIndex is the index of the element you want in the newArray array.

   firstElemIndex..lastElemIndex is used when you want consecutive indexes to be in the sliced array.

2. To add elements at the end of an array:

   push(@interleavedArray,$newArray1[elemIndex]);
   

   Where $newArray1[elemIndex] is the element from @newArray1 you want to add to @interleavedArray

3. To add elements in order:

   Just do a for loop:

   for my $index (0..3){
       push(@interleavedArray,$newArray1[$index]);
       push(@interleavedArray,$newArray2[$index]);
       push(@interleavedArray,$newArray3[$index]);
       push(@interleavedArray,$newArray4[$index]);
       }