Core Java Interview Questions

What is Java?

Java is a high-level, object-oriented programming language that is designed to be platform-independent.

Explain the main features of Java.

Features include platform independence, object-oriented, simple, secure, portable, robust, multithreaded, and dynamic.

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

== compares object references, while .equals() compares object content.

Explain the concept of multithreading in Java.

Multithreading allows concurrent execution of two or more threads.

What is the difference between ArrayList and LinkedList?

ArrayList uses a dynamic array, while LinkedList uses a doubly linked list.

Java EE (Enterprise Edition):

What is Java EE and its key components?

Java EE (Enterprise Edition) is a set of specifications that extend the Java SE (Standard Edition) to provide enterprise features. Key components include Servlets, JSP, EJB, JPA, etc.

Explain the role of Servlets in Java EE.

Servlets are Java programs that run on the server, handling client requests and generating dynamic web content.