Re: How to create multiple keys in a hash

If I understand correctly, you want to count the occurences of elements of a list. If so, this might help.

#!/usr/bin/perl 

use strict;
use warnings FATAL => 'all';

my @colours = (  "red", "green", "yellow", "green", "yellow", "green",
+ "blue", "red", "green");

my %count;

$count{ $_ }++ for @colours;

print "$_\t$count{ $_ }\n" for keys %count;

__END__
output
green   4
blue    1
red     2
yellow  2
[download]

Hope this helps

thinker

Comment on Re: How to create multiple keys in a hash Download Code

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Re: Re: How to create multiple keys in a hash by tanuja (Initiate) on Sep 20, 2003 at 23:32 UTC
Hello, That code will work sice the list is only one. I want to count the occurence of the combination of the lists. and also to know how to map them. i have 3 lists @list1 ={sunny,windy} @list2 = {t,f,b} @list3 = {a,b} and i have records sunny t a sunny t b sunny f a sunny f a sunny b b windy f a windy f b and so on , so i want to know te occurence of all combinations of these records. then i want to count the occurence of sunny,t,a and sunny,t,b and sunny,f,a and sunny,f,b, windy,t,a, ..... so the hash should have multiple keys i.e from list1,list2,list3. and i could craete this as i have described in my question. but i dont know how to retrive. i.e i have an entry "sunny,f,b " how can i know its frequency. Please kindly let me know. Thanks	[reply]
Re: Re: How to create multiple keys in a hash by Anonymous Monk on Sep 20, 2003 at 23:40 UTC
Hi, In my reply the records seem to be mangled. I will have records as follows (sunny,a,b) (sunny,f,b) (sunny,f,a) (windy,t,a) and so on. ... so what is the occurence of each such record which is a combination of keys from the 3 lists. Tanuja.	[reply]


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