It shouldn't be particular to exists(), it should be a general rule: autovivification should only happen to lvalues. When non-lvalues are evaluated, they short-circuit as soon as they encounter an undefined component, and return undef. exists() naturally returns false when checking a component of an undef (e.g., your latter example evaluates as exists(undef, 'c')).

Of course, there's probably some code by now that relies on autovivification of non-lvalues, and that argues strongly against implementing this suggestion. I can't think of any other arguments against it, though doubtless someone else can.

We're not really tightening our belts, it just feels that way because we're getting fatter.

In reply to Exists and autovivification (was: Looping through a hash reference...) by Roy Johnson
in thread Looping through a hash reference is creating a key...? by the_slycer

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