Are the following two snippets functionally equivalent? When I do it the first way, I get a bunch of `use of uninitialized value` warnings because I try to evaluate the nonexistent `$seen{$key}`. Hoping to avoid this. `$seen{$key}` is always either 1 or undefined, it never takes on any other value throughout the script. 

```
if($seen{$key}=='1'){

    print "key already seen\n";

}else{

    print "key not seen\n";
    #do stuff with key
    $seen{$key}='1';

}

```

~~~~

```
if(!$seen{$key}){
   print "key not seen\n";
   #do stuff with key
   $seen{$key}='1';
}else{

   print "key already seen\n";
}

```