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kotlinkotlin-null-safety

Is !! The same thing as ?. In kotlin?

I've read that using "!!" Instead of "?." In kotlin is not recommended. What is the difference between the 2 when checking for null in variables?

Solution

  • !! - is a developer's way of telling the compiler, trust me, I know this value will not be null. It is an unsafe way of converting a nullable value to a non nullable type. Unsafe meaning that it can throw a NullPointerException if the value is indeed null.

    You can read more about it here.

    ?. - is a developer's way of telling the compiler that in the case where the value is not null, do the rest of the logic followed after the ?. sign. This way is the safe way to access a nullable type.

    You can read more about it here