`??` as a "fallback when undefined" operator

[Andrew]

?? operator has a value by its own.

It can be treated as "fallback when exactly undefined" operator - close to || but for exactly undefined values.

Consider the following:

var zero = 0;
var none; // undefined 

zero || 1 == 1;
zero ?? 1 == 0; // this is the difference from ||

none || 1 == 1;
none ?? 1 == 1;  // for exactly undefined || and ?? behave the same

[Claude Pache]

?? operator has a value by its own.

Of course, but it’s not the business of this proposal (Optional chaining, ?.) to discuss the own value of Nullish coalescing (??), which is a different proposal. For that, see rather: https://github.com/tc39/proposal-nullish-coalescing.

Closing as off-topic.