Which functional interface returns a primitive value?
A. BiPredicate B. CharSupplier C. LongFunction D. UnaryOperator
A.
Option A is the correct answer because BiPredicate takes two generic types and returns a primitive boolean value.
Option B is incorrect, since CharSupplier does not exist in java.util.function.
Option C is also incorrect, since LongFunction takes a primitive long value and returns a generic type.
Remember, Java only includes primitive functional interfaces that operate on double, int, or long.
Finally, Option D is incorrect.
UnaryOperator takes a generic type and returns a generic value.