Hash表之间键比较

romario94

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1^# romario94 发表于 2007-11-28 16:31

Hash表之间键比较

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.

放驴娃

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2^# 放驴娃发表于 2007-11-28 16:52

use List::MoreUtils;

Lonki

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3^# Lonki 发表于 2007-11-28 19:10

my %ha = (a => 1, b => 2, c => 3);
my %hb = (a => 4, d => 5, e => 6);

### keys in ha but not in hb ###
my @list = grep {! exists $hb{$_}} keys %ha;
print @list;