Arrays and Hashes

Pushing and Popping

• A common use of arrays is as a LIFO ( Last In First Out ) stack.
• Perl supports this natively with the push and pop operations.
• Push and pop operations work on the right side of the array. Pushing adds to the right, popping removes from the right.
• Example:
  

  push ( @First, 1); 
  push ( @First, 2); 
  push ( @First, 3); 
  $Result = pop(@First);
  print "$Result"; 
  $Result = pop(@First);
  print "$Result"; 
  $Result = pop(@First);
  print "$Result\n"; 
  ==> 3 2 1 
  

• The second argument to push can be either a scalar or an array.
• Popping from an empty list returns undef.