my %tab = (
  "key1" => "val1",
  "key2" => "val2",
  (...)
 "keyN" => "valN",
);

# read one value
if(exists $tab{$mykey}) {
  print "$tab{$mykey}";
}
 
# iterate :
foreach my $key (sort keys %tab) {
    print "$key=$tab{$key}\n";
}

$tab{$mykey}=$newValue;

$tab{$mykey}=undef;

my @tab=("el1","el2", ... ,"elN");

if(defined $tab[2]) {
  print "$tab[2]\n";
}

# update value in offset :2
if(defined $tab[2]) {
  $tab[2]=$newValue;
}
 
# add element to array:
push(@tab,$newValue);
 
# create new array except first element:
my @newArray = @oldArray[1..(@newArray-1)];

if(defined $tab[2]) {
  $tab[2]=undef;
}

# init string to split :
my $string="el1;el2;el3";
 
# split string using ";" separator :
my @tab=split(";",$string);
 
# iterate :
foreach my $element (@tab) {
  print "$element\n";
}