Three ways: 

@{$audit}{@$copy_fields} = map $_ || '', @{$item}{@$copy_fields};

[download]
$_ ||= '' for @{$audit}{@$copy_fields} = @{$item}{@$copy_fields};

[download]
no warnings 'uninitialized';

[download]

I only recommend the first.

In reply to Re: ||= in Hash Slice by ikegami
in thread ||= in Hash Slice by Brovnik

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