Optional chaining (?.) greatly eases the ability to access a deeply nested property without having to check each stage being valid/defined. It will short-circuit with the value of undefined rather than throwing an error.
if (someObject.foo && someObject.foo.bar && someObject.foo.bar.baz) // Now if (someObject.foo?.bar?.baz)
It can also be used to call functions. If the funciton does not exist, it also will return undefined
if (foo.bar) { foo.bar(); } // Now foo.bar?.()