30 Best Java Interview Questions for Freshers

Top Java Interview Questions for Freshers

Java remains one of the most in-demand programming languages for software development. Whether you’re applying for internships or entry-level roles, it’s crucial to prepare thoroughly. This guide covers Java interview questions for freshers, including core concepts, real-world examples, and detailed answers.

📌 Why Java for Interviews?

Java is object-oriented, platform-independent, and robust—making it a top choice for enterprise applications. As a fresher, being proficient in Java can open doors to roles in backend development, Android development, testing, and more.

🔹 Core Java Interview Questions for Freshers

Q1. What are the features of Java?

Object-Oriented
Platform Independent
Robust
Secure
Multithreaded
Architecture Neutral

Q2. What is the JVM?

JVM (Java Virtual Machine) is an engine that provides a runtime environment to execute Java bytecode. It makes Java platform-independent.

Q3. Explain JDK, JRE, and JVM.

JDK: Java Development Kit – includes tools to compile, debug, and run Java programs.
JRE: Java Runtime Environment – contains JVM and libraries to run Java programs.
JVM: Java Virtual Machine – executes Java bytecode.

Q4. What is a Class in Java?

A class is a blueprint for creating objects. It contains fields and methods.

Q5. What is an Object in Java?

An object is an instance of a class with its own identity and behavior.

🔹 Java Coding Interview Questions

Q6. Write a Java program to check if a number is even or odd.

				
					int num = 5;
if(num % 2 == 0) {
  System.out.println("Even");
} else {
  System.out.println("Odd");
}

Q7. How do you reverse a string in Java?

				
					String original = "FreshBlog";
String reversed = new StringBuilder(original).reverse().toString();
System.out.println(reversed);

Q8. What is the difference between `==` and `.equals()`?

== compares object references.
.equals() compares the actual content.

Q9. What is a constructor in Java?

A constructor initializes an object. It has the same name as the class and no return type.

Q10. What is the difference between `ArrayList` and `LinkedList`?

ArrayList is better for accessing elements.
LinkedList is better for inserting/deleting elements.

🔹 Object-Oriented Concepts in Java

Q11. What are the four pillars of OOP?

Encapsulation
Inheritance
Polymorphism
Abstraction

Q12. Explain method overloading and overriding.

Overloading: Same method name, different parameters.
Overriding: Subclass redefines a method from the parent class.

Q13. What is an abstract class?

An abstract class contains abstract methods and cannot be instantiated.

Q14. What is an interface?

An interface defines a contract. It contains abstract methods that must be implemented.

🔹 Exception Handling in Java

Q15. What is exception handling in Java?

Java’s exception handling manages run-time errors using try, catch, finally, and throw.

Q16. What is the difference between checked and unchecked exceptions?

Checked: Checked at compile time (e.g., IOException)
Unchecked: Checked at runtime (e.g., NullPointerException)

🔹 10 Java Coding Examples for Interviews

Example 1: Swap two numbers without using a third variable

				
					a = a + b;
b = a - b;
a = a - b;

Example 2: Check if a number is prime

				
					boolean isPrime = true;
for(int i = 2; i <= num/2; i++) {
  if(num % i == 0) {
    isPrime = false;
    break;
  }
}

Example 3: Fibonacci series up to 10 numbers

				
					int n1 = 0, n2 = 1;
for(int i = 1; i <= 10; i++) {
  System.out.print(n1 + " ");
  int sum = n1 + n2;
  n1 = n2;
  n2 = sum;
}

Example 4: Palindrome string checker

				
					String input = "madam";
String reversed = new StringBuilder(input).reverse().toString();
System.out.println(input.equals(reversed));

Example 5: Factorial of a number

				
					int fact = 1;
for(int i = 1; i <= num; i++) {
  fact *= i;
}

Example 6: Count vowels in a string

				
					int count = 0;
for(char c : str.toCharArray()) {
  if("aeiouAEIOU".indexOf(c) != -1) count++;
}

Example 7: Find duplicate elements in an array

				
					Set<Integer> seen = new HashSet<>();
for(int num : arr) {
  if(!seen.add(num)) System.out.println("Duplicate: " + num);
}

Example 8: Find the largest number in an array

				
					int max = arr[0];
for(int num : arr) {
  if(num > max) max = num;
}

Example 9: Remove white spaces from a string

				
					String cleaned = input.replaceAll("\\s", "");

Example 10: Find factorial using recursion

				
					int factorial(int n) {
  if(n == 0) return 1;
  return n * factorial(n - 1);
}

🔹 FAQs: Java Interview Questions for Freshers

Q1. What is the best way to prepare for a Java interview?

Understand core Java concepts.
Practice coding daily.
Study real interview questions.
Focus on object-oriented principles and Java syntax.

Q2. Do freshers need to learn frameworks like Spring?

Not mandatory, but basic knowledge of Spring and Hibernate helps you stand out.

Q3. What topics should I focus on as a fresher?

Core Java
OOP Concepts
Exception Handling
Collections Framework
Basic coding problems

Q4. Can Java be used for backend development?

Yes. Java is widely used in backend development, especially with frameworks like Spring Boot.

Q5. Are Java coding interviews difficult for freshers?

They can be challenging but manageable with consistent practice and understanding of core topics.

🔹 Final Tips for Cracking Java Interviews

Revise Java basics, including syntax and logic.
Practice short programs and real-world examples.
Mock interviews can help you gain confidence.
Follow industry blogs like Freshy Blog for regular updates.

✅ Read More

👉 Explore more tech interview prep on Freshy Blog for smart career success!