100+ Artech Infosystems Interview Questions and Answers

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 parent class Animal can have child classes like Dog, Cat, and Bird, each with their own unique implementation of the method 'makeSound'.

• Polymorphism makes code more flexible and reusable.

Encapsulation is the process of hiding implementation details and providing a public interface for accessing the functionality.

• Encapsulation helps in achieving data abstraction and information hiding

• It prevents unauthorized access to the internal details of an object

• It allows for easy modification of implementation without affecting the external code

• Example: A class with private variables and public methods

• Example: A bank account class with methods to deposit, withdraw and ch...read more

Overriding in Python is the ability of a subclass to provide a specific implementation of a method that is already provided by its superclass.

• In Python, when a subclass provides a specific implementation of a method that is already defined in its superclass, it is called method overriding.

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

• This allows the subclass to provide a specialized versi...read more

Constructor is a special type of method used to initialize objects in Java.

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

• They do not have a return type, not even void.

• The 'this' keyword in Java is used to refer to the current object.

• Example: public class Car { public Car() { this.make = 'Toyota'; } }

SQL queries for fetching data

• Use SELECT statement to fetch data from a table

• Use WHERE clause to filter data based on conditions

• Use JOIN to combine data from multiple tables

• Use GROUP BY to group data based on a column

• Use ORDER BY to sort data based on a column

Data structures are ways of organizing and storing data in a computer so that it can be accessed and used efficiently.

• Arrays - a collection of elements of the same type

• Linked Lists - a sequence of nodes where each node contains a reference to the next node

• Stacks - a collection of elements with two main operations: push (add) and pop (remove)

• Queues - a collection of elements with two main operations: enqueue (add) and dequeue (remove)

• Trees - a hierarchical data structure with ...read more

Class is a blueprint for creating objects. Primary key is a unique identifier for a record in a database table.

• Class defines the properties and methods of an object

• Primary key ensures uniqueness of a record in a table

• Class can be instantiated to create multiple objects

• Primary key can be a single column or a combination of columns

• Example: Class - Car, Primary key - VIN (Vehicle Identification Number)

Plan Bind is a feature in Oracle database that allows binding of execution plans to SQL statements.

• Plan Bind helps in improving the performance of SQL statements by reusing the execution plan.

• It reduces the overhead of parsing and optimizing the SQL statement every time it is executed.

• Plan Bind is enabled by default in Oracle database.

• It can be disabled using the initialization parameter OPTIMIZER_FEATURES_ENABLE.

• Plan Bind is also known as Cursor Sharing.

• Example: SELECT * FRO...read more

Run-Time polymorphism is the ability of an object to take on many forms at runtime.

• It is achieved through method overriding and virtual functions.

• It allows a subclass to provide its own implementation of a method that is already provided by its parent class.

• It is also known as dynamic polymorphism.

• Example: Animal class with a virtual method 'makeSound', and subclasses Dog and Cat that override the 'makeSound' method.

• When a method is called on an object, the actual method call...read more

Python OOPS concepts and differences between pandas, list, and tuple

• Python OOPS concepts include inheritance, polymorphism, and encapsulation

• Pandas is a library for data manipulation and analysis

• Lists are mutable and can contain different data types

• Tuples are immutable and can contain different data types

Spring profiles allow for different configurations to be used based on the environment.

• Spring profiles are used to define different configurations for different environments such as development, testing, and production.

• Profiles can be activated using the 'spring.profiles.active' property in the application.properties file.

• Profiles can also be activated programmatically using the 'SpringApplication.setAdditionalProfiles()' method.

• Profiles can be used to define different beans,...read more

Inheritance is a mechanism in object-oriented programming where a new class is created by inheriting properties of an existing class.

• Inheritance allows code reuse and promotes code organization.

• The existing class is called the parent or superclass, and the new class is called the child or subclass.

• The child class inherits all the properties and methods of the parent class and can also add its own unique properties and methods.

• For example, a class Animal can be a parent class,...read more

Object-oriented programming (OOP) is a programming paradigm that uses objects to represent and manipulate data.

• OOP is based on the concept of classes and objects.

• It provides encapsulation, inheritance, and polymorphism as key features.

• Encapsulation hides the internal details of an object and provides a public interface.

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

• Polymorphism allows objects of different classes to be treated as objects of a ...read more

Stack is a data structure that follows Last In First Out (LIFO) principle. Queue is a data structure that follows First In First Out (FIFO) principle.

• Stack is like a stack of plates, where the last plate added is the first one to be removed.

• Queue is like a queue of people waiting in line, where the first person added is the first one to be served.

• Stack operations: push (add element), pop (remove top element), peek (get top element without removing).

• Queue operations: enqueue (...read more

C is a procedural language while C++ is an object-oriented language.

• C++ supports classes and objects while C does not.

• C++ has built-in support for polymorphism and inheritance while C does not.

• C++ has a more complex syntax than C.

• C++ allows function overloading while C does not.

• C++ has a standard template library (STL) while C does not.

Python is a high-level, interpreted language known for its simplicity and readability, while C++ is a low-level, compiled language known for its performance and efficiency.

• Python is dynamically typed, while C++ is statically typed.

• Python uses indentation for code blocks, while C++ uses curly braces.

• Python has automatic memory management, while C++ requires manual memory management.

• Python is often used for web development and data analysis, while C++ is commonly used for syste...read more

Exception hierarchy refers to the organization of exception classes in a hierarchical structure.

• Exceptions are organized in a tree-like structure with a base class at the top and derived classes below it.

• The base class is usually the Exception class, and derived classes can be created to handle specific types of exceptions.

• Examples of derived classes include IOException, NullPointerException, and ArithmeticException.

• Exceptions can be caught and handled using try-catch blocks,...read more

The Startup class is used in .NET Core to configure the application's services and middleware.

• The Startup class is typically found in the Program.cs file of a .NET Core application.

• It contains two important methods: ConfigureServices and Configure.

• The ConfigureServices method is used to configure the application's services, such as dependency injection.

• The Configure method is used to configure the application's middleware pipeline.

• The Startup class is responsible for setting ...read more

ConcurrentHashMap is a thread-safe implementation of HashMap in Java.

• It allows multiple threads to read and write to the map concurrently.

• It uses a technique called lock striping to achieve high concurrency.

• It divides the map into segments and locks each segment separately.

• It provides better performance than Hashtable and synchronized HashMap.

• Example: ConcurrentHashMap map = new ConcurrentHashMap<>();

The candidate is asked to explain a simple code snippet.

• Explain the purpose of the code

• Describe the logic or algorithm used in the code

• Discuss any potential improvements or optimizations

Loggers are used to record events and messages in software applications for debugging and analysis purposes.

• Loggers help in identifying and fixing errors in software applications

• They provide a detailed record of events and messages that occur during the execution of the application

• Loggers can be configured to record specific types of events or messages

• They can also be used to monitor application performance and usage

• Examples of loggers include Log4j, Java Util Logging, and Ap...read more

Program to generate Fibonacci series.

• Declare variables for first two numbers of the series

• Use a loop to generate subsequent numbers

• Add the previous two numbers to get the next number

• Print the series or store in an array

Object-oriented programming paradigm focusing on objects and classes for code organization and reusability.

• Encapsulation: bundling data and methods that operate on the data into a single unit (class)

• Inheritance: ability of a class to inherit properties and behavior from another class

• Polymorphism: ability to present the same interface for different data types

• Abstraction: hiding the complex implementation details and showing only the necessary features

Bubble sort program sorts an array by repeatedly swapping adjacent elements if they are in wrong order.

• Compare adjacent elements and swap if necessary

• Repeat until no swaps are needed

• Time complexity: O(n^2)

• Space complexity: O(1)

Data structures are ways of organizing and storing data in a computer so that it can be accessed and used efficiently.

• Data structures are used to manage large amounts of data efficiently.

• They can be implemented using arrays, linked lists, trees, graphs, and other methods.

• Examples include stacks, queues, hash tables, and binary search trees.

• Choosing the right data structure for a particular problem is important for optimizing performance.

• Data structures are a fundamental conce...read more

Oops concepts are the principles of Object-Oriented Programming, including Inheritance, Encapsulation, Polymorphism, and Abstraction.

• Inheritance: Allows a class to inherit properties and behavior from another class.

• Encapsulation: Bundling data and methods that operate on the data into a single unit.

• Polymorphism: Ability of a function to behave differently based on the object it is acting upon.

• Abstraction: Hiding the complex implementation details and showing only the necessar...read more

If else can be used in JCL to conditionally execute steps based on certain criteria.

• IF statement can be used to check for a condition and execute a step or skip it

• ELSE statement can be used to execute a different step if the condition is not met

• Examples include checking for file existence or job completion status

Inheritance is a mechanism where a new class inherits properties and behaviors from an existing class, while abstraction is a concept where only relevant information is shown and unnecessary details are hidden.

• Inheritance allows a class to inherit properties and behaviors from another class, promoting code reusability.

• Abstraction focuses on showing only relevant information and hiding unnecessary details, making the code more manageable and easier to understand.

• Inheritance es...read more

Binding by copy creates a new copy of the object, while binding by reference creates a reference to the original object.

• Binding by copy creates a new independent copy of the object, any changes made to the copy do not affect the original object.

• Binding by reference creates a reference to the original object, any changes made to the reference affect the original object.

• In programming languages like Java, passing objects as parameters to methods can be done by copy or by refere...read more

XML is a markup language used to store and transport data.

• XML stands for eXtensible Markup Language

• It uses tags to define elements and attributes to provide additional information

• XML can be parsed in Java using libraries like DOM, SAX, and StAX

• DOM creates a tree structure of the XML document in memory

• SAX reads the XML document sequentially and triggers events for each element

• StAX is a combination of DOM and SAX, allowing for both sequential and tree-based parsing

Dependency injection is a design pattern that allows objects to receive dependencies rather than creating them internally.

• It helps to decouple the code and makes it more testable and maintainable.

• It allows for easier swapping of dependencies without changing the code.

• There are three types of dependency injection: constructor injection, setter injection, and interface injection.

• Example: Instead of creating a database connection object inside a class, the object is passed as a ...read more

Program to check if a given string is a palindrome or not.

• Convert the string to lowercase to ignore case sensitivity.

• Use two pointers, one at the beginning and one at the end of the string.

• Compare the characters at both pointers and move them towards each other until they meet.

• If all characters match, the string is a palindrome.

• If any character doesn't match, the string is not a palindrome.

OOPs stands for Object-Oriented Programming. It is a programming paradigm based on the concept of objects.

• OOPs focuses on creating objects that contain both data and functions.

• It emphasizes on encapsulation, inheritance, and polymorphism.

• Examples of OOPs languages are Java, C++, Python, etc.

Recursion function to calculate factorial of a number

• Define a function that calls itself with a smaller input until a base case is reached

• Base case should return a value without calling the function again

• Example: Factorial calculation - factorial(n) = n * factorial(n-1)

Different types of joins in SQL with examples

• Inner Join: Returns rows when there is a match in both 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 rows when there is a match in either table

There are 3 types of Subfile types in software engineering.

• Single-level subfile

• Double-level subfile

• Multiple-level subfile

Heap sort is a comparison-based sorting algorithm that uses a binary heap data structure.

• It divides the input into a sorted and an unsorted region.

• It repeatedly extracts the largest element from the unsorted region and inserts it into the sorted region.

• It has a time complexity of O(n log n) and is not stable.

• Example: [8, 5, 3, 1, 9, 6, 0, 7, 4, 2] -> [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

Cond parameter is used to conditionally render elements in React.

• It is a ternary operator that takes three arguments.

• The first argument is the condition to be evaluated.

• The second argument is the element to be rendered if the condition is true.

• The third argument is the element to be rendered if the condition is false.

• It can be used to render different elements based on the state of the component.

Index and subscript are used in COBOL to access elements in arrays.

• Index is used to access a specific element in an array based on its position

• Subscript is used to access a specific element in an array based on its value

• Both index and subscript can be used interchangeably in COBOL

• Example: ARRAY(3) is the same as ARRAY(3:3)

My weakness is time management. I tend to get caught up in details and lose track of time.

• Time management

• Getting caught up in details

• Losing track of time

Oops concepts are fundamental principles of object-oriented programming such as inheritance, polymorphism, encapsulation, and abstraction.

• Inheritance: Allows a class to inherit properties and behavior from another class.

• Polymorphism: Allows objects to be treated as instances of their parent class.

• Encapsulation: Bundling data and methods that operate on the data into a single unit.

• Abstraction: Hides the complex implementation details and only shows the necessary features of an...read more

Object-oriented programming concepts that help in organizing and structuring code.

• Encapsulation: Bundling data and methods that operate on the data into a single unit.

• Inheritance: Allowing a class to inherit properties and behavior from another class.

• Polymorphism: Ability for objects to be treated as instances of their parent class.

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

Overriding is a feature in object-oriented programming where a subclass provides its own implementation of a method that is already defined in its superclass.

• Overriding allows a subclass to provide a specific implementation of a method that is already defined in its superclass.

• The method signature (name, parameters, and return type) must be the same in both the superclass and subclass.

• The subclass method must have the same or a more accessible access modifier than the supercl...read more

OOPs is used for creating modular, reusable and maintainable code.

• Encapsulation: Hiding implementation details and exposing only necessary information.

• Inheritance: Reusing code and creating a hierarchy of classes.

• Polymorphism: Using a single interface to represent multiple entities.

• Abstraction: Reducing complexity by hiding unnecessary details.

• Examples: Java, C++, Python, Ruby, etc.

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

• HashMap uses an array of buckets to store key-value pairs

• Each bucket contains a linked list of entries with the same hash code

• When a key-value pair is added, its hash code is used to determine the bucket and the entry is added to the linked list

• When a value is retrieved, the key's hash code is used to find the bucket and the linked list is searched for the entry with the matchi...read more

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.

• Objects: Instances of classes that encapsulate data and behavior.

• Classes: Blueprint for creating objects, defining their properties and methods.

• Inheritance: Allows a class to inherit properties and behavior from another class.

• Polymorphism: Ability for objects to be treated as instances of their parent class.

• Encapsulation: Bundling data...read more

Arrays are data structures that store a collection of elements of the same data type in contiguous memory locations.

• Arrays are indexed starting from 0.

• Operations include accessing elements by index, inserting elements, deleting elements, and updating elements.

• Example: array of strings - ['apple', 'banana', 'cherry']

map applies a function to each element and returns a new array, flatMap applies a function that returns an array and flattens the result

• map transforms each element of an array using a function and returns a new array

• flatMap applies a function that returns an array and flattens the result

• map returns an array of the same length as the original, flatMap can return an array of a different length

• Example: [1, 2, 3].map(x => [x, x * 2]) returns [[1, 2], [2, 4], [3, 6]]

• Example: [1, 2...read more

Integration runtimes are used to connect different systems and applications. There are three types: Self-hosted, Azure, and SSIS.

• Self-hosted integration runtime is installed on a local machine or a virtual machine and is used to connect to on-premises data sources.

• Azure integration runtime is a cloud-based service that connects to cloud and on-premises data sources.

• SSIS integration runtime is used to run SSIS packages in Azure Data Factory.

• Integration runtimes are used in Azu...read more

Sorting an array of strings without using inbuilt function.

• Implement bubble sort algorithm

• Compare adjacent elements and swap if necessary

• Repeat until no more swaps are needed

Implement a stack using a queue data structure.

• Create two queues, q1 and q2.

• Push operation: Enqueue the element to q1.

• Pop operation: Dequeue all elements from q1 to q2 except the last one. Dequeue the last element from q1 and return it. Swap q1 and q2.

• Top operation: Dequeue all elements from q1 to q2 except the last one. Dequeue the last element from q1 and return it. Enqueue the element to q2. Swap q1 and q2.

• isEmpty operation: Check if both q1 and q2 are empty.

A function is a block of code that performs a specific task when called.

• Functions can take input parameters and return output values.

• Functions can be reused multiple times in a program.

• Examples: summing two numbers, sorting an array, calculating factorial.

Microservices are a software development technique where an application is composed of small, independent services that communicate with each other.

• Microservices are small, independent services that work together to form an application

• Each microservice is responsible for a specific function or feature

• Microservices communicate with each other through APIs

• Microservices can be developed, deployed, and scaled independently

• Examples of companies using microservices include Netflix,...read more

Calculate the sum of elements in an array of strings.

• Convert each string element to integer before adding them up.

• Handle cases where strings are not valid integers.

• Consider using a loop or built-in functions like reduce() in JavaScript.

Yes, I am willing to relocate for the right opportunity.

• I am open to exploring new locations and cultures.

• I am willing to consider relocation packages and assistance.

• I am excited about the prospect of working with a new team in a new environment.

IAM policy in AWS controls access to AWS services and resources

• IAM policies are JSON documents that define permissions

• Policies can be attached to users, groups, or roles

• IAM policies consist of statements that specify actions, resources, and effect

• Example: {"Effect": "Allow", "Action": "s3:GetObject", "Resource": "arn:aws:s3:::examplebucket/*"}

Spring Boot is a framework for building standalone, production-grade Spring-based applications.

• Spring Boot simplifies the process of creating and deploying Spring-based applications.

• It provides a range of features such as auto-configuration, embedded servers, and production-ready metrics.

• Spring Boot is highly customizable and can be used with a variety of other Spring projects and libraries.

Bubble sort is a simple sorting algorithm that repeatedly steps through the list, compares adjacent elements and swaps them if they are in the wrong order.

• Bubble sort compares adjacent elements and swaps them if they are in the wrong order

• It repeats this process until the list is sorted

• It has a time complexity of O(n^2)

• It is not efficient for large datasets

A Trie is a tree data structure used for efficient retrieval of key-value pairs, commonly used in autocomplete features.

• Trie stands for retrieval tree or prefix tree

• Each node in a Trie represents a single character

• Tries are commonly used in search engines for autocomplete suggestions

• Example: Trie for words 'apple', 'app', 'apricot' would have nodes 'a' -> 'p' -> 'p' -> 'l' -> 'e', 'a' -> 'p' -> 'p', 'a' -> 'p' -> 'r' -> 'i' -> 'c' -> 'o' -> 't'

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 in a single query.

• Common types of joins include inner join, left join, right join, and full outer join.

• Joins are performed using the JOIN keyword and specifying the join condition.

• The result of a join is a new table that combines the rows from the joined tables based on the specified condition.

Async Await is a feature in JavaScript that allows for asynchronous programming using Promises.

• Async Await is a syntactic sugar for Promises in JavaScript.

• It allows for writing asynchronous code that looks synchronous.

• Async functions return a Promise, which can be awaited for the result.

• It helps in avoiding callback hell and writing cleaner code.

• Example: async function fetchData() { await fetch('https://api.example.com/data'); }

Python is used for its simplicity, readability, versatility, and vast libraries.

• Easy to learn and read code

• Versatile for various applications like web development, data analysis, machine learning

• Extensive libraries like NumPy, Pandas, and TensorFlow

• Support for object-oriented, imperative, and functional programming styles

Abstraction is the concept of hiding complex implementation details and showing only the necessary information to the user.

• Abstraction allows programmers to focus on the essential features of an object while hiding unnecessary details.

• It helps in reducing complexity and improving the efficiency of the code.

• For example, in object-oriented programming, abstract classes and interfaces are used to achieve abstraction.

Use nested loops to print a star shape

• Use two nested loops, one for rows and one for columns

• Print '*' for the required positions to form the star shape

• Adjust the loop conditions to create different sizes or shapes of stars

MVC is a software architecture pattern that separates an application into three interconnected components: Model, View, and Controller.

• Model represents the data and business logic of the application

• View is responsible for rendering the user interface

• Controller handles user input and updates the model and view accordingly

• MVC promotes separation of concerns and modularity

• Examples of MVC frameworks include Ruby on Rails, ASP.NET MVC, and Spring MVC

Object-oriented programming paradigm that focuses on objects and classes for code organization and reusability.

• OOP is based on the concept of objects, which can contain data in the form of fields (attributes) and code in the form of procedures (methods).

• Classes are blueprints for creating objects, defining their structure and behavior.

• Encapsulation allows bundling data and methods that operate on the data within a single unit, preventing direct access from outside.

• Inheritance...read more

I am proficient in multiple programming languages including Java, Python, and C++.

• Java

• Python

• C++

OOPs concepts are the foundation of object-oriented programming, focusing on principles like inheritance, encapsulation, polymorphism, and abstraction.

• Inheritance: Allows a class to inherit properties and behavior from another class.

• Encapsulation: Bundling data and methods that operate on the data into a single unit.

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

• Abstraction: Hiding the complex implementation details and showing only the necessary...read more

SQL order of operations determines the sequence in which SQL statements are executed.

• The order of operations is: FROM, WHERE, GROUP BY, HAVING, SELECT, ORDER BY.

• Parentheses can be used to change the order of operations.

• Example: SELECT * FROM table WHERE column = value ORDER BY column ASC;

• Example: SELECT column1, COUNT(column2) FROM table GROUP BY column1 HAVING COUNT(column2) > 10;

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

• Encapsulation: Bundling data and methods that operate on the data into a single unit (class)

• Inheritance: Allowing a class to inherit properties and behavior from another class

• Polymorphism: Ability to present the same interface for different data types

• Abstraction: Hiding the complex implementation details and showing only the necessary features

Triggers are special stored procedures that are automatically executed in response to certain events or actions in SQL.

• Triggers can be used to enforce business rules and data integrity.

• They can be used to audit changes to data.

• Triggers can be used to replicate data to other tables or databases.

• They can be used to send notifications or alerts based on certain conditions.

• Examples of events that can trigger a trigger include INSERT, UPDATE, and DELETE statements.

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.

• Encapsulation: Bundling data and methods that operate on the data into a single unit.

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

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

Java is a popular programming language known for its platform independence and extensive libraries.

• Platform independence: Java code can run on any platform with a Java Virtual Machine (JVM).

• Object-oriented: Java supports the principles of encapsulation, inheritance, and polymorphism.

• Rich standard library: Java provides a vast collection of pre-built classes and APIs for various tasks.

• Memory management: Java uses automatic garbage collection to manage memory allocation and dea...read more

4 pillars of OOP are Abstraction, Encapsulation, Inheritance, and Polymorphism.

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

• Encapsulation: Binding data and functions together to protect data from outside interference.

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

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

Interceptors in Angular are used to intercept and manipulate HTTP requests and responses.

• Interceptors can be used to add headers, modify requests, handle errors, etc.

• They are implemented as services that implement the HttpInterceptor interface.

• Example: Creating an interceptor to add a token to all outgoing requests.

Oops concept in Java refers to Object-Oriented Programming principles like Inheritance, Encapsulation, Polymorphism, and Abstraction.

• Inheritance allows a class to inherit properties and behavior from another class.

• Encapsulation involves bundling data and methods that operate on the data into a single unit.

• Polymorphism allows objects to be treated as instances of their parent class.

• Abstraction hides the implementation details and only shows the necessary features to the outsid...read more

Developed a web-based project management tool for a startup

• Used React.js for the frontend and Node.js for the backend

• Implemented user authentication and authorization using JWT

• Integrated with third-party APIs such as Trello and Slack

• Implemented real-time updates using WebSockets

• Deployed the application on AWS using EC2 and RDS

Oops concept of c++ involves the principles of object-oriented programming like inheritance, polymorphism, encapsulation, and abstraction.

• Inheritance allows a class to inherit properties and behavior from another class. Example: class B inherits from class A.

• Polymorphism allows objects of different classes to be treated as objects of a common superclass. Example: function overloading.

• Encapsulation hides the internal state of an object and only exposes the necessary functional...read more

TDD is a software development approach where tests are written before the actual code to ensure code quality and functionality.

• Write a failing test that defines a function or improvements of a function.

• Write the minimum amount of code to pass that test.

• Refactor the code to make it clean and maintainable while ensuring all tests still pass.

Stream API is a feature in Java that allows for processing collections of data in a functional and declarative way.

• Stream API provides a set of functional-style operations to manipulate and process data.

• It allows for parallel processing of data, improving performance.

• Stream API supports lazy evaluation, meaning operations are only executed when necessary.

• It can be used with various data sources like collections, arrays, and I/O channels.

• Some common operations include filterin...read more