The ternary operator should be used to return a value. If you aren't making use of that return value and instead executing code (print in this case), then it is being used in void context. Using the ternary like so

print (open(FH,"<".$log) ? "opened" : "unable to open $!"), "\n";
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would be using it correctly (i.e. not void context, it's returning the value to print).

From perldoc -q "void context"

As of Perl 5.8.1 (and confirmed in perldelta for 5.8.1), map is now smart enough to avoid creating that throw-away list if invoked in void context.

So the efficiency issue in using map in a void context being gone (in Perl 5.8.1 and later), the remaining issue is that of style, clarity, and convention.

grep, backticks, and the trinary operator are still examples of where a return-value is still generated regardless of context, and thrown away in void context.



Dave

"If I had my life to live over again, I'd be a plumber." -- Albert Einstein

The ternary operator can be an lvalue. In that case I believe it is in void context. I don't know of any problem with using it in void context as a shorthand if..else construct, either, though I dislike to do that. ($var ? $yes : $no) = some_sub();

Lvalue context is not void context.

$bar = 12;
$bar;             # void context;
$bar = 13;        # lvalue (not void) context

$string = "foobar";
substr($string,0,3);         # void context
substr($string,0,3) = 're';  # lvalue (not void) context
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