two hash tables, keys comparision?

[robertchen117]

let's say I have two hash tables: new, old

How to find out the keys in new, but not in old?
How to find out the keys in old, but not in new?

tell me the quickest way.

Thanks.

 

[Peter Makholm]

How to find out the keys in new, but not in old?
How to find out the keys in old, but not in new?

tell me the quickest way.

What have you tried?

 

[John W. Krahn]

let's say I have two hash tables: new, old

How to find out the keys in new, but not in old?

my @keys_in_new_not_old = grep !exists $old{$_}, keys %new;

How to find out the keys in old, but not in new?

my @keys_in_old_not_new = grep !exists $new{$_}, keys %old;




John

 

[smallpond]

Such a politely phrased request...

BugBear

He did say "Thanks"

 

[A. Sinan Unur]

He did say "Thanks"

where he should have said *please*.

Sinan