Hi all,

What's the best way for creating a new hash which contains the difference between 2 other hases?

I have two hashes built like this:

$new_values{MachineType}{Blue_machine}{Unit}{1}{Channel}{0}{Value}{15}
$new_values{MachineType}{Blue_machine}{Unit}{1}{Channel}{1}{Value}{22}
$new_values{MachineType}{Blue_machine}{Unit}{2}{Channel}{0}{Value}{19}
$new_values{MachineType}{Red_machine}{Unit}{1}{Channel}{0}{Value}{22}


$old_values{MachineType}{Blue_machine}{Unit}{1}{Channel}{0}{Value}{14}
$old_values{MachineType}{Blue_machine}{Unit}{1}{Channel}{1}{Value}{22}
$old_values{MachineType}{Blue_machine}{Unit}{2}{Channel}{0}{Value}{21}

This should be the result:

$end_values{MachineType}{Blue_machine}{Unit}{1}{Channel}{0}{Value}{14}
$end_values{MachineType}{Blue_machine}{Unit}{2}{Channel}{0}{Value}{19}
$end_values{MachineType}{Red_machine}{Unit}{1}{Channel}{0}{Value}{22}


I could itterate over %new_values and compare the keys to %old_values and when they differ copy the thing over to end_values.
But when I have a key that exists in new_values and doesn't exist in old_values, then I would get an error. I could do an "if defined" first but this would bloat the whole thing.
Is there a Module which enables me to do so in a gracious way?

Thanks in advance!

In reply to Get the difference between 2 Hashes by emat

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