Java General

Java is called platform independent because of its byte codes which can run on any system irrespective of its underlying operating system.

• True

• False

Which of these are wrapper classes?

• Integer, Long, Byte, String

• Integer, Long, Byte, Float

• Double, Long, Byte, Float

• Integer, String, Byte, Float

What makes a HashSet different from a TreeSet?

• It does not maintain elements in an ordered way.

• It does not allow the null object.

• It permits the null object.

• The elements are maintained in a sorted order.

Which Set implementation allows duplicate values?

• TreeSet

• Sorted

• LinkedHashSet

• None

A default constructor in Java is created automatically by the Java compiler when the programmer doesn't create any constructor in the entire program

• True

• False

Can you call a constructor of a class inside another constructor?

• No

• Yes

• Only if inherited

What is the difference between equals() and == in Java?

• Equals() method is defined in Object class in Java and used for checking equality of two objects defined by business logic.

  “==” or equality operator in Java is a binary operator provided by Java programming language and used to compare primitives and objects

• There is no difference

How is the creation of a String using new() different from that of a literal?

In Java, the super keyword is a reference variable that refers to an immediate parent class object.

• True

• False

What are access modifiers in Java?