100+ TCS Interview Questions and Answers

A constructor is a special type of method in a class that is automatically called when an object of that class is created.

• Constructors have the same name as the class they belong to

• They are used to initialize the object's state

• They can have parameters to customize the initialization process

A palindrome code reads the same forwards and backwards.

• Create a function that compares the original string with its reverse

• Use built-in functions like reverse() or loop through the string to create the reversed version

• Handle cases where spaces or punctuation may be present in the string

To reverse a string, iterate through it in reverse order and append each character to a new string.

• Create an empty string to store the reversed string

• Iterate through the original string in reverse order using a loop

• Append each character to the new string using the += operator

• Return the reversed string

Yes, I am proficient in programming with experience in multiple languages and projects.

• Proficient in multiple programming languages such as Python, Java, and C++

• Experience working on various projects including web development, data analysis, and software engineering

• Strong problem-solving skills and ability to write efficient and clean code

I learned coding through online courses, coding bootcamps, and self-study.

• Took online courses on platforms like Coursera, Udemy, and Codecademy

• Attended a coding bootcamp to gain hands-on experience and mentorship

• Self-studied using resources like books, tutorials, and coding challenges

OOPs concepts refer to Object-Oriented Programming principles like Inheritance, Encapsulation, Polymorphism, and Abstraction.

• Inheritance: Allows a class to inherit properties and behavior from another class. Example: Parent class 'Animal' and child class 'Dog'.

• Encapsulation: Bundling data and methods that operate on the data into a single unit. Example: Class 'Car' with private variables and public methods.

• Polymorphism: Ability to present the same interface for different data...read more

Joins in SQL are used to combine rows from two or more tables based on a related column between them.

• Joins are used to retrieve data from multiple tables based on a related column

• Common types of joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN

• Example: SELECT * FROM table1 INNER JOIN table2 ON table1.column = table2.column

DDL is used to create, modify or delete database objects while DML is used to manipulate data within those objects.

• DDL stands for Data Definition Language and includes commands like CREATE, ALTER, DROP, etc.

• DML stands for Data Manipulation Language and includes commands like SELECT, INSERT, UPDATE, DELETE, etc.

• DDL commands are used to create, modify or delete database objects like tables, indexes, etc.

• DML commands are used to manipulate data within those objects like insertin...read more

Deep learning is a subset of machine learning that uses neural networks to learn from large amounts of data.

• Deep learning is a type of machine learning that uses neural networks with multiple layers to learn patterns from data

• It is particularly effective for tasks such as image and speech recognition, natural language processing, and autonomous driving

• Examples of deep learning frameworks include TensorFlow, PyTorch, and Keras

Oops stands for Object-Oriented Programming. It is a programming paradigm that uses objects to represent and manipulate data.

• Oops is a programming paradigm

• It focuses on using objects to represent data and perform operations

• It promotes code reusability, modularity, and flexibility

• Examples of object-oriented programming languages include Java, C++, and Python

Different types of JOIN in DBMS include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.

• INNER JOIN: Returns rows when there is at least one match in both tables.

• LEFT JOIN: Returns all rows from the left table and the matched rows from the right table.

• RIGHT JOIN: Returns all rows from the right table and the matched rows from the left table.

• FULL JOIN: Returns rows when there is a match in one of the tables.

A program to find prime numbers in a given range or up to a certain number.

• Iterate through numbers from 2 to n, checking if each number is divisible by any number from 2 to its square root.

• Use a boolean array to mark non-prime numbers and return the list of prime numbers.

• Optimize by only checking odd numbers after 2, as all other even numbers are not prime.

Print repeating elements in an array of strings

• Iterate through the array and use a hashmap to store the frequency of each element

• Print elements with frequency greater than 1

A palindrome number is the same when read forwards and backwards.

• Convert the number to a string to easily check for palindrome

• Reverse the string and compare it with the original string to check for palindrome

• If the reversed string is equal to the original string, then the number is a palindrome

OOPS in JAVA refers to Object-Oriented Programming concepts like classes, objects, inheritance, polymorphism, and encapsulation.

• OOPS stands for Object-Oriented Programming

• Key concepts include classes, objects, inheritance, polymorphism, and encapsulation

• Java is an object-oriented programming language that follows OOPS principles

• Example: Creating a class 'Car' with properties like 'make', 'model', and methods like 'drive', 'stop'

Tuple is immutable and ordered while list is mutable and ordered.

• Tuple uses () while list uses []

• Tuple is faster than list for accessing elements

• Tuple can be used as keys in dictionaries while list cannot

• Tuple is used for heterogeneous data while list is used for homogeneous data

Oops concepts are fundamental principles of object-oriented programming that help in organizing and designing code.

• Encapsulation: Bundling data and methods that operate on the data into a single unit (class). Example: Class Car with properties like make, model, and methods like start(), stop().

• Inheritance: Allows a class to inherit properties and behavior from another class. Example: Class Truck inheriting from class Vehicle.

• Polymorphism: Ability of objects to take on multipl...read more

Reverse a given string

• Use a loop to iterate through the characters of the string

• Append each character to a new string in reverse order

• Return the reversed string

HTTP is a protocol used for transferring data over the internet, while IP is a unique address assigned to devices on a network.

• HTTP stands for Hypertext Transfer Protocol and is used for transmitting web pages, images, videos, etc. between a web server and a client's browser.

• IP stands for Internet Protocol and is a numerical label assigned to each device connected to a network to identify and locate them.

• HTTP operates at the application layer of the OSI model, while IP operat...read more

Use regular expressions to sanitize strings by removing unwanted characters or patterns.

• Use regex patterns to match and replace unwanted characters or patterns in the string.

• For example, to remove all non-alphanumeric characters from a string: str.replace(/[^a-zA-Z0-9]/g, '')

• Be careful with regex patterns to ensure that only the intended characters are removed.

Oops in C++ stands for Object-Oriented Programming System. It is a programming paradigm that uses objects and classes for data organization and manipulation.

• Oops in C++ allows for encapsulation, inheritance, and polymorphism.

• Classes in C++ are used to create objects, which can have attributes (data members) and behaviors (member functions).

• Example: class Car { private: int speed; public: void accelerate() { speed += 10; } };

• Example: Car myCar; myCar.accelerate();

Stateful vs stateless refers to whether or not the server retains information about the client between requests.

• Stateful: Server retains client information between requests

• Stateless: Server does not retain client information between requests

• Stateful example: HTTP cookies

• Stateless example: RESTful APIs

Code to check if a given array of strings are palindromes

• Iterate through each string in the array

• Reverse the string and compare it with the original string to check for palindrome

• Return true if it is a palindrome, false otherwise

Keys in SQL are used to uniquely identify rows in a table and establish relationships between tables.

• Keys ensure data integrity by enforcing uniqueness and relationships between tables

• Primary key uniquely identifies each row in a table

• Foreign key establishes a relationship between two tables

Gen AI refers to the next generation of artificial intelligence that is capable of learning, adapting, and evolving on its own.

• Gen AI utilizes advanced machine learning algorithms to continuously improve its performance

• It can analyze vast amounts of data to make predictions and decisions

• Gen AI has the potential to revolutionize industries such as healthcare, finance, and transportation

Inheritance is a way to create a new class from an existing class while polymorphism is the ability of an object to take on many forms.

• Inheritance allows a subclass to inherit properties and methods from a superclass.

• Polymorphism allows objects of different classes to be treated as if they are of the same class.

• Inheritance is a way to achieve code reusability while polymorphism allows for flexibility in code design.

• Example of inheritance: class Dog extends Animal

• Example of po...read more

Overriding is a concept in object-oriented programming where a subclass provides a specific implementation of a method that is already provided by its superclass.

• Occurs in inheritance when a subclass provides a specific implementation of a method that is already provided by its superclass

• The method in the subclass must have the same name, return type, and parameters as the method in the superclass

• Allows for polymorphism, where a subclass can be treated as an instance of its s...read more

A constructor is a special type of method in a class that is automatically called when an object of that class is created.

• Constructors have the same name as the class they belong to

• They can be used to initialize object properties

• They do not have a return type

• Example: public class Car { public Car() { // constructor code here }}

Java supports polymorphism, allowing objects of different classes to be treated as objects of a common superclass.

• Polymorphism is achieved through method overriding and method overloading.

• Polymorphism allows for code reusability and flexibility.

• Example: Animal class with subclasses like Dog and Cat, where they can be treated as objects of the Animal class.

OOP is a programming paradigm based on the concept of objects, which can contain data in the form of fields and code in the form of procedures.

• OOP focuses on creating objects that interact with each other to solve problems.

• Objects have attributes (data) and methods (functions) that define their behavior.

• Encapsulation, inheritance, and polymorphism are key principles of OOP.

• Example: In a car simulation program, a 'Car' object could have attributes like 'color' and 'speed', and...read more

The OSI layer in serial order refers to the Open Systems Interconnection model which is a conceptual framework used to understand network communication.

• Physical Layer

• Data Link Layer

• Network Layer

• Transport Layer

• Session Layer

• Presentation Layer

• Application Layer

Abstraction focuses on hiding implementation details, while interfaces define a contract for classes to implement.

• Abstraction allows for defining common behavior without specifying implementation details

• Interfaces define a set of methods that a class must implement, providing a contract for how the class should behave

• Abstraction can be achieved through abstract classes in languages like Java

• Interfaces are used to achieve multiple inheritance in languages like C#

To reverse a string in C++, you can use the reverse function from the algorithm library.

• Include the algorithm header file: #include

• Use the reverse function with begin() and end() iterators

• Example: string str = 'hello'; reverse(str.begin(), str.end());

Find duplicates in a list of strings

• Iterate through the array and store each element in a hash set

• If an element is already in the hash set, it is a duplicate

Yes, I can write programs in various programming languages.

• Proficient in languages like Python, Java, C++, etc.

• Experience with data structures and algorithms

• Able to develop web applications, mobile apps, and more

A function that reverses a given string and returns it.

• Create an empty string to store the reversed string

• Iterate through the input string from the end to the beginning and append each character to the new string

• Return the reversed string

To reverse an array of strings in C++, use the std::reverse function.

• Include the header to use the std::reverse function.

• Call std::reverse with the beginning and ending iterators of the array.

• Example: std::reverse(arr.begin(), arr.end());

I worked on various projects during my undergraduate studies.

• Developed a mobile app for a class project

• Participated in a research study on environmental sustainability

• Collaborated with classmates on a group presentation for a business course