TCS Java Interview Guide for Freshers (2025)

Alright, so you’ve got your TCS technical interview coming up, and you've put "Java" down as your language of choice. You've probably spent weeks, maybe months, learning the syntax, doing problems, and memorizing definitions.

But here’s a secret: the interviewer has heard the textbook definitions a thousand times. They don't want a robot who can recite what final, finally, and finalize are. They want to have a conversation with a person who actually understands the concepts and can talk about them normally.

So, let's go over how to handle the two parts of your technical evaluation, the coding test and the actual interview, like a real person.

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Part 1: The Coding Round - Just You and the Code

This is the practical part. They give you a problem, a time limit, and a basic code editor. Your job is to make it work. They aren't trying to trick you with impossible questions; they just want to see if you can think logically and write clean Java code.

What kind of problems pop up? Honestly, it's almost always about Arrays and Strings. They are the bread and butter of these tests. Get really comfortable with them. Think about things like: finding duplicates, checking if a string is a palindrome, reversing a sentence, that sort of stuff.

Let's walk through a common problem: The Anagram Check.

The interviewer asks you to write a program to see if "listen" and "silent" are anagrams.

Your first thought might be, "Okay, if they're anagrams, they must have the same letters." Good start! Your brain might then jump to, "I can sort both words. If they become the same after sorting, they're anagrams!"

That's a perfectly good solution. It shows you can think logically.

But let's think about how to write the code for it in a way that's clean and simple.

Java

import java.util.Arrays; // We need this for sorting arrays

public class AnagramSolver {

    public static void main(String[] args) {
        String word1 = "listen";
        String word2 = "silent";

        // First, a quick sanity check. Are they the same length?
        if (word1.length() != word2.length()) {
            System.out.println("Nope, not anagrams.");
            return; // Exit the program
        }

        // Let's turn them into character arrays so we can sort them
        char[] word1Chars = word1.toCharArray();
        char[] word2Chars = word2.toCharArray();

        // The magic happens here
        Arrays.sort(word1Chars);
        Arrays.sort(word2Chars);

        // Now, let's see if the sorted arrays are equal
        if (Arrays.equals(word1Chars, word2Chars)) {
            System.out.println("Yes, they are anagrams!");
        } else {
            System.out.println("Nope, not anagrams.");
        }
    }
}

The comments in the code explain the thought process. This is exactly what you should be doing in your head during the test. Break the problem down into tiny, manageable steps.

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Part 2: The Technical Interview— The Real Conversation

This is where your personality comes into play. The interviewer will ask you questions to see how deep your understanding goes. Don't just spit out definitions. Explain them in your own words.

Let's tackle some classic Java questions.

1. "Can you tell me the difference between JDK, JRE, and JVM?"

This one is almost guaranteed to come up. It sounds like alphabet soup, but it's simple.

How to answer it like a human: "Sure. I think of it like building and using a toy car. The JVM (Java Virtual Machine) is like the engine. It's the core part that actually makes the car run, but it can't do anything on its own. The JRE (Java Runtime Environment) is the rest of the car—the wheels, the body, the seats. It's everything you need to use the car. So, if you just want to run a Java program someone else made, you only need the JRE. But if you want to build your own car, you need the JDK (Java Development Kit). The JDK is the whole factory, it includes the JRE, plus all the tools like wrenches and screwdrivers (the compiler and debugger) that you need to build the car from scratch."

2. "What are the OOPs concepts?"

Don't just list the four words. Anyone can memorize those. Show you understand them.

How to answer it like a human: "There are the four main pillars: abstraction, encapsulation, inheritance, and polymorphism. Instead of just defining them, I find it easier to think about them with an example. Take Abstraction. It’s basically 'need-to-know'. When I send a WhatsApp message, I just type and hit send. I don't need to know about the complex networking that happens behind the scenes. That's abstraction. Or inheritance, which is just about code reusability. You create a 'Vehicle' class with basic properties, and then your 'Car' and 'Bike' classes can inherit those, so you don't have to write the same code over and over again."

3. "What's the deal with final, finally, and finalize?"

This is a classic "gotcha" question. They want to see if you can distinguish between three things that sound alike.

How to answer it like a human: Ah, the three F's! They're actually completely different.

• final It is like a permanent marker. If you make a variable final, its value can't be changed. If you make a class final, no other class can inherit from it. It's for making things constant.
• finally  It is all about cleanup. It's a block of code that you use with a try-catch statement. The code inside the finally block is guaranteed to run, whether an error happened or not. You use it for things like closing a file to make sure it always gets closed.
• And finalize... honestly, I know it's a method that the garbage collector is supposed to call before an object is destroyed, but I've also read that it's unpredictable and not really used in modern Java programming anymore.

Being honest about finalize being outdated shows you're not just repeating old notes; you're aware of modern practices.

Final Thoughts Before You Go In

Look, the goal here isn't to be a walking encyclopedia of Java. The goal is to show that you're a logical thinker who is passionate about technology and can communicate clearly.

It's okay to say, "That's a great question. Can I take a moment to think about it?" It's better than rushing to the wrong answer. Be curious, be polite, and let them see you're excited about the opportunity. You'll do great.

Also Read: How to Answer TCS HR Interview Questions (2025 Freshers Guide)