instanceof with generic collection

Question

Why would the following snippet not compile ?

if (mangoList instanceof List<Mango>) { System.out.println("true"); }

• You don't know that mangoList is a List type.
• The instanceof keyword only works on primitive types.
• You can only check the type of collections using reflection.
• Generic types are erased before runtime.(ans)
• The statement could cause mangoList to be set to an instance of a List.

Which do you think is the correct answer ?

Answer 1

The correct answer is the one that you marked ans. You will be able to tell that mangoList is a List, but you wouldn't be able to get the type of its erased argument. The remaning choices do not make sense.