Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl-Sensitive Sunglasses
 
PerlMonks  

Re: Comparing a value to hash key

by NetWallah (Abbot)
on Nov 14, 2012 at 04:53 UTC ( #1003750=note: print w/ replies, xml ) Need Help??


in reply to Comparing a value to hash key

Is it possible to check a variable against all the keys in a hash
The question suggests you do not understand the fundamental property of a hash.

The primary use of a hash is for a quick and simple lookup of a 'key', by indexing, using curly-braces.

The first line of your code:

if (! exists ($hash{$remoteIP})){
does exactly that - looks up the value of $remoteIP, and can be thought of as comparing with every possible key in %hash, and returning 'true' if the matching one exists.

Your later comparison:

if ($remoteIP ~~ @k){
is a more expensive way of doing the same comparison that the first line does.

             "By three methods we may learn wisdom: First, by reflection, which is noblest; Second, by imitation, which is easiest; and third by experience, which is the bitterest."           -Confucius


Comment on Re: Comparing a value to hash key
Select or Download Code

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://1003750]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others wandering the Monastery: (17)
As of 2015-07-29 16:37 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?

    The top three priorities of my open tasks are (in descending order of likelihood to be worked on) ...









    Results (265 votes), past polls