Category: Java Written Test Questions and Answers

1. You have a Employee class with a public String field departmentName. In you program’s main method,you create a Employee instance e1. What is output of the below code ?…

When a class implements to Comparable interface, what method must also be implemented? compareTo toString compare equals Answer: 1 – CompareTo Which of the following declaration is correct that MAX…

1. What exception will be occurred with below code? int a = 100; int b = getSumOfProducts(); // This method returns 0 values int c = a/b; NullPointerException ArithmeticException IOException…

What is the difference between an interface and an abstract class in Java? In Java, an interface and an abstract class are both used to define a contract for classes…

In Java, a String is an immutable object that represents a sequence of characters. It means once a String is created, its value cannot be changed, any operation that appears…

We can implement a custom class that behaves like an array by creating a class that has an array as a private field, and implements the necessary methods to access…

In this tutorial, we will see serialization and deserialization of Enums and sample java codes. Enums Serialization: Java’s Serializable interface handles serialization of enums in a special way. Enum types…

In this post, we will see more details on SerialVersionUID and also issues with default serial version id. SerialVersionUID: Java uses serialVersionUID field for versionsing. It’s a static and final…