Nullish coalescing operator allows assigning a variable if it's not null or undefined, or an expression otherwise.
a = b ?? other
It is an improvement over previously used || because || will also assign other if b is empty string or other falsy, but not nullish value.
However, sometimes, we also use && for value assignment, for example
a = b && func(b)
where we only want to do func on b if it's not nullish, otherwise assign the nullish b.
Of course, && checks for falsiness, not nullishness. Is there a nullish version of &&?
To my knowledge, there is no such operator and also no proposal to add one. Instead you can rely on the standard way to check for nullish values: b == null
a = b == null ? b : func(b)