You should really use <code> </code> tags around your code. It'll look a lot better, like this: 
#!/usr/bin/perl

use strict;
use warnings;
use Data::Dumper;

my %hash1 = ( key1 => "val1",
              key2 => "val2",
              key3 => "val3",
              key4 => "val4",
              key5 => "val5");
my %hash2 = ( key1 => "xxxval1",
              key2 => "xxxval2");

print Dumper(%hash1), "\n";
out:foreach my $key (keys %hash1)
{
    foreach my $inkey (keys %hash2)
    {
        if($key eq $inkey)
        {
            $hash1{$key} = $hash2{$inkey};
            next out;
        }
    }
}

print Dumper %hash1;

__END__

[download]

However, I put it to you that the nested foreach loops are unnecessary, and that this does the same thing: 

#!/usr/bin/perl

use strict;
use warnings;
use Data::Dumper;

my %hash1 = ( key1 => "val1",
              key2 => "val2",
              key3 => "val3",
              key4 => "val4",
              key5 => "val5");
my %hash2 = ( key1 => "xxxval1",
              key2 => "xxxval2");

print Dumper(%hash1), "\n";

foreach my $inkey (keys %hash2)
{
    if(exists $hash1{$inkey})
    {
        $hash1{$inkey} = $hash2{$inkey};
    }
}

print Dumper %hash1;

__END__

[download]

Because hey! It's a hash! There's no need to loop over the keys to see what's in it.

In reply to Re^2: update a hash with a hash by beable
in thread update a hash with a hash by stupidius

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.