Re: update a hash with a hash

hi the following code must work as far as i understood the question. I assumed that the 2 keys for which values have to be changed are the same as keys in the second hash:

#!/usr/bin/perl

my %hash1 = ( key1 => val1,
              key2 => val2,
              key3 => val3,
              key4 => val4,
              key5 => val5);
              
my %hash2 = ( key1 => xxxval1,
              key2 => xxxval2);
            
out:foreach my $key (keys %hash1)
{
        foreach my $inkey (keys %hash2)
        {
                if($key eq $inkey)
                {
                        $hash1{$key} = $hash2{$inkey};
                        next out;
                }
        }
}
[download]

hope it solves your problem. _{janitored by ybiC: Balanced <code> tags around codeblock}

Comment on Re: update a hash with a hash Download Code

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Re^2: update a hash with a hash by beable (Friar) on Jul 15, 2004 at 10:11 UTC
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.	[reply] [d/l] [select]

Replies are listed 'Best First'.

Re^2: update a hash with a hash
by beable (Friar) on Jul 15, 2004 at 10:11 UTC

#!/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.

[reply]
[d/l]
[select]