- What is the difference between Overloading and Overriding? - What is the difference between soft and weak references? - Can I call the garbage collector explicitly in the code? - What is the difference between List and Set? - What is the difference between String and StringBuffer and StringBuilder? Which one is serializable? - What are volatile and transient in Java? - In which scenario is a HashMap not a suitable structure? - What is the hierarchy involving Collections, List, and Set? - What is a Functional Interface? - What is a default method? - Can I add more methods in a Functional Interface? - Can I use Functional Interfaces in Streams? - What is the difference between Functional Interface and Predicate? - What is the difference between array and ArrayList? - What is the difference between Stack and Heap memories? - Why can't I use primitive type in Generics? - How to use primitive types in Generics? - What does lambda offer to Java? - How to measure an application's performance?