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What does the optional chaining operator ?. do?

A Throws an error if the value is null
B Returns undefined instead of throwing when accessing a property of null or undefined
C Provides a default value
D Makes a property optional in a class

Answer

Returns undefined instead of throwing when accessing a property of null or undefined

obj?.a?.b short-circuits to undefined if any link is null or undefined, avoiding a TypeError. The ?? operator supplies a default value.

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