Is there an “opposite” to the null coalescing operator? (…in any language?)

Question

null coalescing translates roughly to return x, unless it is null, in which case return y

I often need return null if x is null, otherwise return x

Answer 1

If you've got a special kind of short-circuit boolean logic, you can do this (javascript example):

return x && x.y;

If x is null, then it won't evaluate x.y.