From: "Christopher Humphries" <[EMAIL PROTECTED]>
> Can anyone shed light on this problem?
>
> I noticed some strange behaviour with a hash whilst writing a
> subroutine.
>
> What happens is that if I pass a hash by reference to a subroutine,
> traverse that hash using a while() loop, and return in the middle of
> the loop, the hash is corrupted in some way.
>From the man pages:
When the hash is entirely read, a null array is returned in list
context (which when assigned produces a false ("0") value), and
"undef" in scalar context. The next call to "each" after that will start
iterating again. There is a single iterator for each hash, shared by
all "each", "keys", and "values" function calls in the program; it can
be reset by reading all the elements from the hash, or by
evaluating "keys HASH" or "values HASH".
This means that if you leave the while( ($k,$v) = each %hash)
before it finishes iterating over the whole hash then the keys or
each that follow will ONLY read the REST of the hash.
So it would be best to eval
each %hash;
in void context if you do so. :
while( my( $key, $value ) = each %{$hash} ) {
if( $value eq 'value1' ) {
each %$hash;
return;
}
}
Jenda
=========== [EMAIL PROTECTED] == http://Jenda.Krynicky.cz ==========
There is a reason for living. There must be. I've seen it somewhere.
It's just that in the mess on my table ... and in my brain.
I can't find it.
--- me
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