200+ Mitra SK Interview Questions and Answers

Software is a collection of data, programs, procedures, instructions, and documentation that perform tasks on a computer system.

• Software is essential for computers to be useful.

• It includes programs, libraries, and non-executable data.

• Software and hardware work together to enable modern computing systems.

• Examples of software include operating systems, web browsers, and games.

Interview questions for a software developer on topics like class vs struct, vectors, Linux commands, inheritance, and pointer safety.

• Replacing class with struct changes the default access level to public

• Vector is a dynamic array that can be resized at runtime

• Elements can be added to vector using push_back() or insert() function

• Inheritance allows a derived class to inherit properties and methods from a base class

• To call base class function with derived class object, use scope...read more

Questions related to Python programming language and concepts.

• List and tuple are data structures in Python. List is mutable while tuple is immutable.

• Shallow copy creates a new object but references the original object's elements.

• Some libraries in Python are NumPy, Pandas, Matplotlib, and Scikit-learn.

• Python's current version is 3.9. You can find it on Command prompt by typing 'python --version'.

• OOPS in Python stands for Object-Oriented Programming. It allows for creating clas...read more

Java does not support multiple inheritance, but interfaces can inherit multiple interfaces.

• Java does not allow a class to inherit from multiple classes, but it can implement multiple interfaces.

• Interfaces can inherit from multiple interfaces using the 'extends' keyword.

• For example, interface C can extend interfaces A and B: 'interface C extends A, B {}'

Static variables are variables that are shared among all instances of a class. Arrays are a data structure that stores a collection of elements. Collections are classes in Java that store and manipulate groups of objects. C++ and Java differ in syntax, memory management, and platform independence. Java architecture consists of JVM, JRE, and JDK. Java is a high-level programming language known for its platform independence. Object-oriented programming (OOP) is a programming pa...read more

Yes, I have experience in programming.

• I have a Bachelor's degree in Computer Science.

• I have worked as a software developer for 3 years.

• I am proficient in programming languages like Java, C++, and Python.

• I have developed web applications using frameworks like React and Angular.

• I have experience in database management with SQL and NoSQL databases.

• I have worked on projects involving data analysis and machine learning algorithms.

Explanation of OOPs concepts with an example

• OOPs stands for Object-Oriented Programming

• Encapsulation - Binding data and functions that manipulate the data together

• Inheritance - A class can inherit properties and methods from another class

• Polymorphism - Ability of an object to take many forms

• Abstraction - Hiding implementation details and showing only functionality

• Example: A car is an object that has properties like color, model, and methods like start, stop, accelerate

• Encapsu...read more

Multithreading in Java allows concurrent execution of multiple threads.

• Java provides built-in support for multithreading through the java.lang.Thread class.

• Threads can be created by extending the Thread class or implementing the Runnable interface.

• The start() method is used to start a new thread, which calls the run() method.

• Synchronization mechanisms like synchronized blocks and locks can be used to control access to shared resources.

• Java also provides high-level concurrency...read more

A procedure is a set of instructions that performs a specific task, while a function is a procedure that returns a value.

• Procedures are used to perform actions, while functions are used to calculate and return values.

• Procedures do not have a return statement, while functions always have a return statement.

• Functions can be called within expressions, while procedures cannot.

• Procedures can have input parameters, while functions can have both input parameters and a return value.

Object oriented programming 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.

• Objects are instances of classes, which define the structure and behavior of the objects.

• Encapsulation is the concept of bundling data and methods that operate on the data within a single unit, such as a class.

• Inheritance allows classes to inherit attributes and methods from other classes.

• Polymorphism allows obj...read more

Display data of two tables by joining them using a common column.

• Use SQL JOIN statement to combine data from two tables based on a common column.

• Choose the appropriate type of JOIN based on the relationship between the tables.

• Specify the columns to be displayed in the SELECT statement.

• Use aliases to differentiate between columns with the same name in both tables.

• Apply any necessary filters or sorting to the result set.

There are two important categories of software: System software and Application software.

• System software: manages and controls computer hardware so that application software can perform its tasks. Examples: Operating systems, device drivers, firmware.

• Application software: performs specific tasks for the user. Examples: Word processors, web browsers, games.

Join the tables on a common column and display the combined data.

• Identify the common column in both tables

• Use JOIN statement to combine the tables

• Select the columns to display

• Apply any necessary filters or sorting

• Display the data in a table or list format

Java supports multithreading through the java.lang.Thread class and java.util.concurrent package.

• Java threads are created by extending the Thread class or implementing the Runnable interface.

• Threads can be started using the start() method.

• Synchronization can be achieved using synchronized keyword or locks.

• Java provides several classes and interfaces to support concurrent programming such as Executor, ExecutorService, Future, etc.

• Thread pools can be created using ExecutorServi...read more

To display data of two tables, we can use JOIN operation in SQL.

• Identify the common column(s) between the two tables.

• Use JOIN operation to combine the data from both tables based on the common column(s).

• Choose the appropriate type of JOIN operation (INNER, LEFT, RIGHT, FULL) based on the requirement.

• Use SELECT statement to display the required columns from the combined table.

• Example: SELECT t1.column1, t2.column2 FROM table1 t1 JOIN table2 t2 ON t1.common_column = t2.common_c...read more

Multithreading is the ability of a program to perform multiple tasks concurrently.

• Multithreading allows for better utilization of CPU resources

• It can improve program performance and responsiveness

• Examples include running multiple downloads simultaneously or updating a GUI while performing a background task

• Synchronization is important to prevent race conditions and ensure thread safety

Primary key uniquely identifies a record in a table, while unique key ensures uniqueness of a column.

• Primary key cannot have null values, while unique key can have one null value.

• A table can have only one primary key, but multiple unique keys.

• Primary key is used as a foreign key in other tables, while unique key is not.

• Example: Employee ID can be a primary key, while email address can be a unique key.

A software developer is responsible for designing, coding, testing, and maintaining software applications.

• Designing software solutions based on client requirements

• Writing code in various programming languages

• Testing and debugging software to ensure functionality

• Maintaining and updating software applications

• Collaborating with team members to achieve project goals

A trigger is a special type of stored procedure that automatically executes in response to certain events.

• Triggers are used to enforce business rules or to perform complex calculations.

• Syntax: CREATE TRIGGER trigger_name {BEFORE | AFTER} {INSERT | UPDATE | DELETE} ON table_name FOR EACH ROW {trigger_body}

• Example: CREATE TRIGGER audit_log AFTER INSERT ON employees FOR EACH ROW INSERT INTO audit VALUES (NEW.id, 'inserted', NOW())

Primary key uniquely identifies a record in a table, while unique key ensures uniqueness of a column.

• Primary key cannot have null values, while unique key can have null values.

• A table can have only one primary key, but multiple unique keys.

• Primary key is automatically indexed, while unique key may or may not be indexed.

• Example: Employee ID can be a primary key, while email address can be a unique key.

My favorite programming language is Python because of its simplicity, readability, and versatility.

• Python is known for its clean and readable syntax, making it easy to learn and understand.

• Python has a large standard library with built-in modules for various tasks, reducing the need for external libraries.

• Python is versatile and can be used for web development, data analysis, artificial intelligence, and more.

Increasing the sides of a rectangle by 20% increases its area by 44%.

• Calculate the new dimensions of the rectangle after increasing the sides by 20%.

• Use the formula for the area of a rectangle to calculate the new area.

• Compare the new area to the original area to determine the percentage increase.

Do-While loop executes the code block once before checking the condition, while loop checks the condition first.

• Do-While loop is used when the code block needs to be executed at least once.

• While loop is used when the code block may not need to be executed at all.

• Do-While loop is less efficient than While loop as it always executes the code block at least once.

• Example of Do-While loop: do { //code block } while (condition);

• Example of While loop: while (condition) { //code bloc...read more

OOPs is a programming paradigm based on the concept of objects, while multithreading is the ability of a CPU to execute multiple threads concurrently, and abstraction is the process of hiding implementation details while showing only the necessary information.

• OOPs is based on the concept of objects, which encapsulate data and behavior

• Multithreading allows for concurrent execution of multiple threads, improving performance

• Abstraction is the process of hiding implementation det...read more

Different types of HTML tags include block-level tags, inline tags, empty tags, and self-closing tags.

• Block-level tags: <div>, <p>, <h1>

• Inline tags: <span>, <a>, <strong>

• Empty tags: <img>, <br>, <input>

• Self-closing tags: <img />, <br />

Method is a named block of code that can be called multiple times, while a block is a group of statements enclosed in curly braces.

• A method has a name and can accept parameters, while a block does not.

• A method can return a value, while a block cannot.

• A method can be called from anywhere in the program, while a block is only accessible within the scope it was defined.

• Example of a method: public int add(int a, int b) { return a + b; }

• Example of a block: if (condition) { int x =...read more

Polymorphism is the ability of an object to take on many forms.

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

• It is achieved through method overriding and method overloading.

• Example: A shape class can have different subclasses like circle, square, triangle, etc. and all of them can be treated as shapes.

• Example: A method can have different implementations in different classes but can be called using the same name.

• Example: The + o...read more

State management is the process of managing the state of an application or system.

• It involves storing and updating data that represents the current state of the application.

• State can be managed locally or globally, depending on the architecture of the application.

• Common techniques for state management include using local state, global state, and state containers like Redux.

• Examples of state management in action include updating the UI based on user input, managing user authen...read more

Interface vs abstract, required vs include, method overriding vs overloading

• Interface is a contract that defines methods that must be implemented by a class, while abstract class can have implemented methods

• Required is used to specify mandatory dependencies in a module, while include is used to import code from another file

• Method overriding is when a subclass provides its own implementation of a method from its superclass, while overloading is when a class has multiple method...read more

The view gets to know that a binded property has been changed in the viewmodel through data binding mechanisms.

• Data binding mechanisms like two-way binding or event listeners are used to notify the view of property changes in the viewmodel.

• Frameworks like Angular, React, or Vue.js provide built-in mechanisms for handling property changes in the viewmodel.

• ViewModels often implement observable patterns or use libraries like RxJS to notify the view of property changes.

Ambition box is a term used to describe a person's goals, aspirations, and desires for their future.

• Represents a person's dreams and objectives

• Can include career goals, personal achievements, and life milestones

• Often used in career development discussions or personal growth planning

Software development problems

• Bugs and errors

• Compatibility issues

• Lack of documentation

• Poor performance

• Security vulnerabilities

JavaScript selectors are used to select and manipulate HTML elements.

• Selectors can be used with methods like getElementById(), getElementsByClassName(), and querySelector().

• Selectors can target specific elements based on their tag name, class, ID, attributes, and more.

• Selectors can also be combined to create more complex queries.

• Examples: document.getElementById('myElement'), document.querySelector('.myClass')

Constraints are limitations or restrictions that are put in place to ensure certain requirements are met.

• Constraints can be physical, such as the size of a database or the amount of memory available

• Constraints can also be logical, such as business rules or security requirements

• Constraints can help ensure data integrity and prevent errors or security breaches

• Examples of constraints include primary keys, foreign keys, check constraints, and unique constraints

View state is a feature in ASP.NET that preserves the state of server-side controls between postbacks.

• View state is used to maintain the state of server-side controls between postbacks.

• It is a hidden field on the page that stores the values of the controls.

• View state can be disabled to improve performance, but it may cause issues with control state.

• Example: A text box retains its value even after a postback due to view state.

The question is asking about how a specific implementation is done in Java.

• Explain the implementation details of the specific feature or functionality in Java

• Provide code examples if applicable

• Discuss any relevant libraries or frameworks used in the implementation

Python program to find the count of a letter in a sentence

• Use the count() method on the string to find the number of occurrences of a specific letter

• Convert the sentence to lowercase to make the search case-insensitive

• Handle both uppercase and lowercase versions of the letter to get an accurate count

TCS stands for Tata Consultancy Services.

• TCS is a multinational IT services and consulting company based in India.

• It is one of the largest IT services firms in the world.

• TCS provides services in areas such as software development, infrastructure management, and business process outsourcing.

Java code to check if a given String is a palindrome or not.

• Create a function that takes a String as input

• Use two pointers, one starting from the beginning and one from the end, to compare characters

• If all characters match, return true; otherwise, return false

While loop executes only if the condition is true, do-while loop executes at least once before checking the condition.

• While loop checks the condition first, then executes the code block

• Do-while loop executes the code block first, then checks the condition

• While loop may not execute at all if the condition is false initially

• Do-while loop always executes at least once before checking the condition

Static variables are variables that retain their values throughout the program's execution and are accessed using the class name.

• Static variables are declared using the 'static' keyword.

• They are shared among all instances of a class.

• Static variables are accessed using the class name followed by the dot operator.

• Example: ClassName.staticVariableName;

React is a JavaScript library for building user interfaces.

• React is a declarative, efficient, and flexible library for building user interfaces.

• It allows developers to create reusable UI components.

• React follows a component-based architecture where UI is broken down into smaller components.

• React lifecycle consists of three main phases: Mounting, Updating, and Unmounting.

• During Mounting, a component is created and inserted into the DOM.

• During Updating, a component re-renders w...read more

Data encapsulation is the concept of bundling data and methods that operate on that data within a single unit.

• Data encapsulation helps in hiding the internal state of an object and restricting access to it.

• It allows for better control over the data by preventing external interference.

• Encapsulation also promotes code reusability and modularity.

• Example: In object-oriented programming, a class encapsulates data (attributes) and methods (functions) that operate on that data.

Use SQL query with MAX function to find highest salary from employees table.

• Use SELECT MAX(salary) FROM employees;

• Make sure to replace 'employees' with the actual table name if different.

• Ensure the column name for salary is correct in the query.

Security is implemented in our application through encryption, authentication, and authorization mechanisms.

• We use encryption algorithms to secure sensitive data both at rest and in transit.

• Authentication is implemented through secure login mechanisms like OAuth or JWT.

• Authorization controls access to different parts of the application based on user roles and permissions.

TCS benefits include health insurance, retirement plans, paid time off, and professional development opportunities.

• Health insurance coverage for employees and their families

• Retirement plans such as 401(k) with employer match

• Paid time off for vacation, sick leave, and holidays

• Professional development opportunities like training programs and certifications

A variable is a container that holds a value. There are different types of variables in programming.

• Variables are used to store data in a program

• They can be assigned different values during runtime

• Types of variables include integers, floats, strings, booleans, and more

• Variables can be declared with a specific data type or left untyped

• Examples: int age = 25, float price = 9.99, string name = 'John Doe'

Multithreading is the ability of a CPU to execute multiple threads concurrently.

• Multithreading improves performance by utilizing idle CPU time.

• Threads share the same memory space, allowing for efficient communication.

• Examples include web servers handling multiple requests and video games rendering graphics while processing user input.

Design patterns are reusable solutions to common problems in software design.

• Creational patterns - Singleton, Factory, Builder

• Structural patterns - Adapter, Decorator, Facade

• Behavioral patterns - Observer, Strategy, Template Method

Confidential refers to information that is meant to be kept private, while over confidential implies an excessive level of secrecy.

• Confidential information is sensitive and should only be shared with authorized individuals.

• Over confidential suggests an unnecessary or excessive level of secrecy beyond what is required.

• Examples of confidential information include trade secrets, personal data, and classified documents.

• An example of over confidential behavior could be refusing to...read more

Cloud computing is the delivery of computing services over the internet, including servers, storage, databases, networking, software, analytics, and intelligence.

• Cloud computing allows users to access resources on-demand without the need for physical infrastructure.

• It offers scalability, flexibility, and cost-efficiency compared to traditional on-premises solutions.

• Examples of cloud computing providers include Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platf...read more

The latest version of Android is Android 12.

• Android 12 was released on October 4, 2021.

• It includes new features such as Material You design, privacy enhancements, and improved performance.

• It is currently available for select devices and will roll out to more in the coming months.

Python supports single, multiple, multilevel, hierarchical, and hybrid inheritance.

• Single Inheritance: A class can inherit from only one base class.

• Multiple Inheritance: A class can inherit from multiple base classes.

• Multilevel Inheritance: A class can inherit from a derived class, creating a chain of inheritance.

• Hierarchical Inheritance: Multiple derived classes inherit from a single base class.

• Hybrid Inheritance: Combination of multiple and multilevel inheritance.

Circular linked list is a linked list where the last node points back to the first node, forming a circle.

• Allows for efficient traversal from the end of the list to the beginning

• Useful for applications where data needs to be accessed in a circular manner, such as round-robin scheduling

• Can be used to implement a circular buffer in data structures

Multithreading and servlets are important concepts in Java for concurrent programming and web development.

• Multithreading allows multiple threads to run concurrently, improving performance and responsiveness of applications.

• Servlets are Java classes that handle HTTP requests and generate responses, used for web development.

• Multithreading can be used in servlets to handle multiple requests simultaneously.

• However, care must be taken to ensure thread safety and avoid race conditi...read more

The init method in Python is used as a constructor to initialize the object's attributes when an instance of a class is created.

• Init method is called automatically when a new object is created from a class.

• It is used to initialize the object's attributes or perform any setup required for the object.

• The init method is defined with the __init__ function in Python.

Lists allow duplicate elements and maintain insertion order, while sets do not allow duplicates and do not maintain order.

• Lists allow duplicate elements, while sets do not

• Lists maintain insertion order, while sets do not

• Lists are implemented using classes like ArrayList or LinkedList, while sets are implemented using classes like HashSet or TreeSet

OOPs stands for Object-Oriented Programming. Pillars of OOPs are Inheritance, Encapsulation, Abstraction, and Polymorphism.

• OOPs 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.

• Pillars of OOPs include Inheritance (ability of a class to inherit properties and behavior from another class), Encapsulation (binding data and methods that manipulate the data into a single unit), Abstraction (hi...read more

Java is platform-independent, object-oriented, and has automatic memory management, while C++ is platform-dependent, supports multiple inheritance, and requires manual memory management.

• Java is platform-independent, while C++ is platform-dependent

• Java is object-oriented, while C++ supports both procedural and object-oriented programming

• Java has automatic memory management (garbage collection), while C++ requires manual memory management

• Java does not support multiple inheritan...read more

Primary key uniquely identifies a record in a table, while unique key ensures uniqueness of a column.

• Primary key is a column or set of columns that uniquely identifies each record in a table

• Primary key cannot have null values

• A table can have only one primary key

• Unique key ensures that a column or set of columns have unique values

• Unique key can have null values

• A table can have multiple unique keys

Friend function is not a concept in Java.

• Friend function is a concept in C++ where a non-member function can access private and protected members of a class.

• Java does not have the concept of friend function.

• In Java, access to private and protected members of a class is restricted to the class itself and its subclasses.

HashMap is a data structure that stores key-value pairs and uses hashing to efficiently retrieve values.

• HashMap internally uses an array of linked lists to store key-value pairs.

• When a key-value pair is added, the key is hashed to find the index in the array where the pair will be stored.

• If multiple keys hash to the same index, a linked list is used to handle collisions.

• HashMap allows null keys and values, and can have one null key and multiple null values.

• Example: HashMap ma...read more

The 4 basic principles of OOPS are Abstraction, Encapsulation, Inheritance, and Polymorphism.

• Abstraction: Hiding complex implementation details and showing only necessary information.

• Encapsulation: Binding data and functions together and restricting access to them.

• Inheritance: Creating new classes from existing ones, inheriting properties and methods.

• Polymorphism: Ability of objects to take on multiple forms or behaviors.

C and C++ are programming languages used for system and application development. Debugging is the process of finding and fixing errors in code.

• C is a procedural language used for system programming and embedded systems.

• C++ is an object-oriented language used for application development and game programming.

• Debugging involves using tools like breakpoints, print statements, and debuggers to identify and fix errors in code.

• Common debugging techniques include step-by-step executi...read more

Types of variables in Python include integers, floats, strings, lists, tuples, dictionaries, and booleans.

• Integers: whole numbers without decimal points (e.g. 5, -3)

• Floats: numbers with decimal points (e.g. 3.14, -0.5)

• Strings: sequences of characters enclosed in quotes (e.g. 'hello', '123')

• Lists: ordered collections of items enclosed in square brackets (e.g. [1, 'apple', True])

• Tuples: ordered collections of items enclosed in parentheses (e.g. (1, 'banana', False))

• Dictionaries...read more

OOPs concepts are essential in software development as they provide a structured approach to designing and organizing code.

• Encapsulation: Helps in bundling data and methods together, providing data security and code reusability.

• Inheritance: Allows code reuse and promotes code organization by creating a hierarchy of classes.

• Polymorphism: Enables objects to take on multiple forms, allowing flexibility and extensibility in code.

• Abstraction: Simplifies complex systems by breaking...read more

Inheritance is a concept in object-oriented programming where a class inherits properties and behaviors from another class.

• Allows a class to inherit attributes and methods from another class

• Promotes code reusability and reduces redundancy

• Creates a parent-child relationship between classes

• Derived class can override or extend the functionality of the base class

Use a before insert trigger to update records before they are inserted into the database.

• Create a before insert trigger on the object you want to update records for.

• Write the logic in the trigger to update the records as needed.

• Make sure to test the trigger thoroughly before deploying it to production.

Multithreading allows multiple threads to run concurrently, improving performance and responsiveness.

• Multithreading is used to execute multiple tasks simultaneously within a single process.

• It can improve performance by utilizing multiple CPU cores efficiently.

• Common multithreading libraries include Java's Thread class and C#'s Task Parallel Library.

• Example: In a web server, multithreading can handle multiple client requests concurrently.

• Example: In a video game, multithreadin...read more

SQL Join is used to combine rows from two or more tables based on a related column between them.

• INNER JOIN returns only the matching rows between tables

• LEFT JOIN returns all rows from the left table and matching rows from the right table

• RIGHT JOIN returns all rows from the right table and matching rows from the left table

• FULL OUTER JOIN returns all rows from both tables

• IIS server is a web server used to host web applications

• Project details depend on individual experience