The "default" action is not to do a assignement at all. But using the current value of $foo will do it as JavaFan suggested:

$foo = $bar // $foo;

However this is not much better then

$foo = $bar if defined $bar;

Because the other part of the statement ($foo) is duplicated - if I have a long variable like $myhash{mykey}->{mykey2} instead of $foo it only gets uglier. I was looking for a simple and short syntax like:

$foo =// $bar

But appereantly such operator does not exist in Perl. The best solution I found so far (also ugly but not getting more complex if $foo and $bar are long expressions) is:

{local $_ = $bar; $foo = $_ if defined $_;}

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In reply to Re^2: Assignment to a value only if it is defined by voj
in thread Assignment to a value only if it is defined by voj

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