The case #1 says start with "el", match that, then allow any number of random characters while still allowing the "om" to match. It did that.

Case #2 is similar, except that the letters in-between "el" and last "om" are captured and printed.

Case #3: Your "pop" statement is nonsensical. I have no idea what you mean by this. Perhaps you meant to do that with "@matches"? I will demo that below.

Case #4 splits as "sentence" into 2 words.

#!/usr/bin/perl -w
use strict;

#case 1
my @matches = "hello awesome" =~ /(el).*(om)/;
print "@matches\n";   #prints el om

#case 2
@matches = "hello awesome" =~ /(el)(.*)(om)/;
print "@matches\n";    #prints el lo awes om
                       # (el)(lo awes)(om)

#case 3 nonense!!!
#print pop @awesome; #nonsensical !
                     #there is no array "awesome" and
                     #therefore there is nothing to "pop" from.

#case 4                     
@matches = split (/\s/,"hello awesome");
print "@matches\n";  #prints" hello awesome"
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Update:I printed this in perhaps a more understandable way:

#!/usr/bin/perl -w
use strict;

#case A
my @matches = "hello awesome home" =~ /(el).*(om)/;
foreach (@matches)
{
   print $_,"\n";
}
## el
## om

#case B
@matches = "hello awesome home" =~ /(el)(.*)(om)/;
foreach (@matches)
{
   print $_,"\n";
}
## el              this is the (el)
## lo awesome h    now there is another "om" before last om
## om              this is last (om)

#Case C
#lets say that we only wanted this stuff between the first (el)
#and the last (om)? And we just want a scalar. 
#this is done with an array slice.

my $stuff = ("hello awesome home" =~ /(el)(.*)(om)/)[1];
print "$stuff\n"; #prints "lo awesome h"

#Case D
my @stuff = "hello awesome home" =~ /(el)(.*)(om)/;
print pop (@stuff)."\n"; #prints: om
print pop (@stuff)."\n"; #prints: lo awesome h
print pop (@stuff)."\n"; #prints: el

#Case E
@stuff = "hello awesome home" =~ /(el)(.*)(om)/;
print shift (@stuff)."\n"; #prints: el
print shift (@stuff)."\n"; #prints: lo awesome h
print shift( @stuff)."\n"; #prints: om
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