# initialize an array at once with 3 scalars, two array pointers and one hash pointer: 
@array= (1,2,3,\@anotherarray,[1,2],{1=>15});

# initialize a hash at once with three keys. Data is one scalar, one hash pointer and one array pointer
%hash= (1=>15, 7=>{5=>4}, 2=>[1,2,3]);

##</code><code>##

foreach ... {
   $array[$i][$j]= $value;
   # or
   push( @{$array[$i]}, $value);


   $hash{$i}{$j}= $value;
}