Java Interview Questions for 2 to 5 Years Experience

In this post, we are going to cover the most frequently asked Java interview questions for a 2 to 5 years experienced Java developer. It contains interview questions not only from common Java topics like arrays, strings, threads, and OOPs but also from Java 8, NIO, Spring Boot, Design Patterns, etc. 

This list contains interview questions suitable for both beginners in Java programming and experienced developers with years of experience.

Java 8 Interview Questions

In this post, we are going to cover some of the most common Java 8 interview questions, along with simple explanations and examples.

Java 8 introduced a lot of new features that changed the way we write code. Understanding these features is important not only for interviews but also for improving your coding skills.

Why String is Immutable in Java with Example

In this post, we are going to learn why the String class is immutable in Java and what that means for developers. We will also look at a simple example to understand this concept better. The question of why String is immutable often gets asked in Java interviews, so knowing about the immutability of strings in detail is important for both Job seekers and experienced Java developers. Let's dive in to understand why Strings in Java are immutable.

Arrays in Java with Coding Examples

In this post, we are going to learn about what is arrays in Java, Syntax for array in Java, How they work, and how it helps us to store multiple elements. We will also go through some simple coding examples to help you understand the concept better.

What is an Array in Java?

An array in Java is a data structure that allows us to store multiple values in a single variable. So Instead of declaring separate variables for each value, we can just create an array to store them all together in a fixed-size list. But in array, we can store only similar type of elements that simply means If we have created an integer array then we are allowed to store only integer type of elements in it and If we try to store other than integer type elements like double or String then we will get an compile time error saying incompatible types.

Strings in Java with Coding Examples

Strings are very important in Java or any other programming language because they are used to store and manipulate text data. We cannot even imagine an application or website without having text on it. In almost every application, we need to work with text data, whether it is accepting input from the user or displaying a message to the user. It is also important to know about Strings and how it works internally if you are preparing for Java interviews. So knowing about Strings in Java is very important for both students and job seekers.

In this tutorial, we will learn what is a String in Java with its different types like String, StringBuffer, and StringBuilder. 

Abstraction in Java with Bank ATM Example

In the previous post we learned what is polymorphism in Java. In this post, we are going to learn about another important concept of OOPs in Java which is Abstraction.

Abstraction in Java simply means hiding certain details from the user and showing only essential information to the user.

• Here is a real-life example of abstraction: Through the ATM machine, banks only show essential information to people, such as withdrawing money and checking account balances, by hiding the internal implementation or mechanism.
• Another real-life example of abstraction is 

Polymorphism in Java with Examples

In the previous post, we learned about what is encapsulation in Java with its examples. In this post, we will learn about polymorphism in Java and how it works. So, without wasting any time, let's get into the discussion.

The term "polymorphism" means having many forms. In simple terms, it refers to the ability of something to exist in different forms or have different behaviors. It allows us to perform a single action in different or multiple ways. 

Here is a real-life example of Polymorphism: