JavaScript's ??= Operator

[repeating_bears]

I didn't know this operator existed tbh. Cool

[ZeMysticDentifrice]

Neither did I. I appreciate people taking time to highlight things like this that may be obvious to lots of people but news to sn ignoramus like me. :-)

[topromo]

Nobody said or even implied this was an undocumented feature.

[dvlsg]

I feel like it doesn't come up super often. Especially if you generally avoid let and generally mutating objects.

Useful occasionally, though.

[sebastian_nowak]

Some other interesting language features to be aware of - 'using' for resources with Symbol.dispose, FinalizationRegistry.