Why am I not getting the expected output?

loops.pl

#!/usr/bin/perl
use strict;
use warnings;

my @a = (1,2,3,4,5);

foreach my $x (@a){
  print "first FOREACH: $x and the array is [@a] \n";
}

while( my $x = shift @a ){
  print "WHILE: $x and the array is [@a]\n";
}

foreach my $x (@a){
  print "second FOREACH: $x and the array is [@a]\n";
}

print "all done\n";