Check for exists:

if (! exists $hash{$key}){ 
    ...
    next;
}

[download]

In the above, it's possible to just say if (! $hash{$key}), but if the hash key's value has something like 0 or anything else false (or undef), the if will be false.

Check if hash key is another hash:

if (! ref $hash{$key} eq 'HASH'){
    ...
    next;
}

[download]

Now, with that said, you're probably best off showing us a piece of your structure and the code that accesses it. Many times, warnings like this are thrown due to the code accessing the structure is doing something we don't expect, and other times it may be because we are misunderstanding what the structure really is in the first place.

-stevieb

Re-parented this (my own) node from considered duplicate I want to check if a particular hash exists or not and not just the key.

In reply to Re: I want to check if a particular hash exists or not and not just the key. by stevieb
in thread Non existent Hash and error"not a hash refernece at perl line" by Anonymous Monk

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