answer

Junior

• Length in bytes for primitive types

• Meaning of keywords: static, final, transient

• 'this' and 'super' keywords

• Contract between equals() and hashCode()

• Access modifiers in Java

• Explain strictfp, volatile, transient

• What different between StringBuffer and StringBuilder

• Purpose, types and creation of nested classes

    top-level classe - 
    nested class - class within another class.
    - It increases encapsulation
    - It is a way of logically grouping classes 
    - More readable: places the code closer to where it is used.
    - nested classes - will be able to access all the class members (include private)
    
        - static nested classes
        - inner classes - associated with an instance of their enclosing top-level-class
        - anonymous inner classes - un-named inner classes
        - local class - is inner class defined inside a method or block ({ ... }) inside a method
        
    URLS:
        https://blogs.oracle.com/darcy/nested,-inner,-member,-and-top-level-classes
  

Regular

• What does it mean that an object or a class is mutable or immutable
• How to make class immutable
• Besides “string” do you know any other immutable classes
• Rules to create equals method
• Difference between overriding and overloading
• How can we replace multi-inheritance pattern in Java
• Can interface inherit from different interface
• What is a marker interface
• Regular vs. static initialization blocks