Quiz-7(Core Java)

What is an inner class in Java?

• A class that is declared inside another class

• A class that has no access to the outer class's members

• A class that can only be instantiated from within the outer class

• A class that cannot have any methods

Which keyword is used to create an instance of an inner class from an outer class?

• new

• inner

• outer

• this

Which of the following is a valid declaration of an inner class?

• public class Outer { private class Inner { } }

• public class Inner { }

• private class Outer { class Inner { } }

• public class Outer { static class Inner { } }

What is the primary benefit of using inner classes in Java?

• Enhanced performance

• Improved code organization and encapsulation

• Reduced memory usage

• Simplified class hierarchy

Which type of inner class can access the private members of the outer class?

• Static inner class

• Local inner class

• Non-static inner class

• Anonymous inner class

What is a local inner class?

• A class with no access modifiers

• A class that can only be instantiated from outside the outer class

• A class that is defined within a static method

• A class declared inside a method or a block of code

Can an inner class access the instance variables of its outer class directly?

• Yes, always

• Yes, but only if the outer class is static

• Yes, but only if the inner class is static

• No, it cannot access instance variables of the outer class directly

Which of the following is NOT a valid way to instantiate an inner class from an outer class?

• Outer.Inner innerObj = outerObj.new Inner();

• Outer outerObj = new Outer(); Inner innerObj = outerObj.new Inner();

• Outer.Inner innerObj = new Outer.Inner();

• Outer.Inner innerObj = new Outer().new Inner();

When is it appropriate to use a lambda expression instead of an anonymous inner class?

• When you need to implement multiple methods from an interface

• When the code is more concise and readable with a lambda expression

• When you need to create a class with a specific name

• When you want to define a class with fields

What is an anonymous inner class in Java?

• A class without a name that can be defined within a method or as an argument to a method

• A class that doesn't have any methods

• class that is automatically generated by the Java compiler

• A class with no fields or constructors