Hi Meir,
You're assigning a new list (of key/value pairs) to the entire hash, so
you overwrite all the existing keys.
To override any set keys and add additional keys, try this:
%hash = (%hash, key => value, key => value, key => value ... );
This is a common pattern for overriding default arguments, for example.
On 04/04/2011 04:26 PM, Meir Guttman wrote:
Hi all!
In one program of mine, I collect key/value pair scattered along the
code using the
* $hash{key} = value;*form.
But sometimes I have a bunch of keys/values that I tried to *add* to
the hash in a single statement in the form of
*%hash = (key => value, key => value, key => value, ... );*
see (executable) script below.
To my surprise, the second form reinitialized the hash and practically
erased whatever was there before. What I was left with is the result
of the last statement.
I cannot find any treatment of this issue in Perl's documentation
(http://perldoc.perl.org/5.10.1/index.html).
This IMHO is inconsistent.
Any comments?
Meir
*#!/usr/bin/perl*
*use strict;*
*my %hash;*
**
*$hash{'01'} = 1;*
*$hash{'02'} = 2;*
*$hash{'03'} = 3;*
*$hash{'04'} = 4;*
**
*print "Before:\n", ("-" x 6), "\n";*
*foreach my $key (sort keys %hash) {print "$key - $hash{$key}\n";}*
**
*%hash = (*
* '05' => 5,*
* '06' => 6,*
* '07' => 7,*
* '08' => 8,*
* );*
**
*print "After:\n", ("-" x 6), "\n";*
*foreach my $key (sort keys %hash) {print "$key - $hash{$key}\n";}*
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