LogicValley Technologies Senior Software Developer Interview Questions and Answers

An interface is a contract that specifies the methods that a class must implement.

• Interfaces define a set of methods that a class must implement.

• Interfaces are used to achieve abstraction and loose coupling.

• Interfaces are commonly used in Java to implement multiple inheritance.

• In my project, I used interfaces to define a common set of methods that multiple classes needed to implement.

Skip, SkipWhile, and SkipLast are LINQ methods used to skip elements in a sequence.

• Skip(n) skips the first n elements in a sequence.

• SkipWhile(predicate) skips elements in a sequence while the predicate is true.

• SkipLast(n) skips the last n elements in a sequence.

• LINQ is a language integrated query that allows querying data from different data sources.

• SQL is a database management system that uses Structured Query Languag...read more

Abstract class is a class that cannot be instantiated, while interface is a contract that a class must implement.

• Abstract class can have both abstract and non-abstract methods, while interface can only have abstract methods.

• A class can implement multiple interfaces, but can only inherit from one abstract class.

• Abstract class can have constructors, while interface cannot.

• Abstract class can have instance variables, while...read more

Runtime polymorphism is achieved through method overriding while compile-time polymorphism is achieved through method overloading.

• Runtime polymorphism is also known as dynamic polymorphism.

• It is achieved through inheritance and method overriding.

• The decision of which method to call is made at runtime based on the object being referred to.

• Compile-time polymorphism is also known as static polymorphism.

• It is achieved thro...read more

IEnumerable and IQueryable are interfaces for querying data, while ArrayList and List are collections for storing data.

• IEnumerable is used for querying data from in-memory collections, while IQueryable is used for querying data from external data sources like databases.

• ArrayList is a non-generic collection that can store any type of object, while List is a generic collection that can store a specific type of object.

• Lis...read more

The controller that renders the view depends on the framework being used.

• In ASP.NET MVC, the controller renders the view

• In AngularJS, the view is rendered by the browser

• In React, the view is rendered by the component

• The controller can pass data to the view for rendering

The controller that consumes the API depends on the architecture of the application.

• In a traditional MVC architecture, the controller would consume the API.

• In a client-server architecture, the client-side controller would consume the API.

• In a microservices architecture, each microservice would have its own controller to consume the API.

• The choice of controller also depends on the programming language and framework used...read more

There are three types of controllers in MVC: 1. View Controller 2. Action Controller 3. Partial View Controller

• View Controller handles user interface and displays data

• Action Controller handles user input and performs actions

• Partial View Controller handles reusable UI components

• Examples: HomeController, AccountController, ProductController

SQL Injection is a type of cyber attack where malicious SQL statements are inserted into an entry field to manipulate the database.

• Use parameterized queries or prepared statements

• Sanitize user input

• Limit database user privileges

• Use a web application firewall

• Regularly update and patch software

Abstract classes are used when we want to provide a default implementation and interfaces are used when we want to enforce a contract.

• Abstract classes can have both abstract and non-abstract methods while interfaces can only have abstract methods.

• A class can implement multiple interfaces but can only inherit from one abstract class.

• Abstract classes can have constructors while interfaces cannot.

• Interfaces are used for a...read more

Constants are values that cannot be changed during program execution, whereas variables can be changed.

• Constants are declared using the 'const' keyword.

• Variables are declared using the 'var' or 'let' keyword.

• Constants must be initialized at the time of declaration.

• Variables can be initialized later in the program.

• Constants are used to declare values that should not be changed, such as mathematical constants.

• Variables a...read more

String is immutable while StringBuilder is mutable.

• String is a sequence of characters that cannot be modified once created.

• StringBuilder is a dynamic object that can be modified and manipulated.

• String concatenation creates a new string object while StringBuilder modifies the existing object.

• String is thread-safe while StringBuilder is not.

• Use String for small strings and StringBuilder for large strings or frequent mani...read more

Value types store data directly, while reference types store a reference to the data's memory location.

• Value types include primitives like int, float, and bool. Example: int x = 5;

• Reference types include objects, arrays, and strings. Example: string name = 'Alice';

• Value types are stored on the stack, while reference types are stored on the heap.

• Modifying a value type creates a new copy, while modifying a reference type...read more

Both array list and list use the type of the elements they contain.

• Array list and list can contain elements of any type, including custom classes.

• The type of the elements is specified when creating the array list or list.

• For example, ArrayList<String> or List<Integer>.

An object is an instance of a class. A class is a blueprint for creating objects.

• A class is a template or blueprint for creating objects

• An object is an instance of a class

• Classes define the properties and methods of objects

• Objects have state and behavior

• Classes can inherit properties and methods from other classes

SP stands for Stored Procedure which is a pre-compiled SQL code while Query is a statement used to retrieve data from a database.

• SP is faster than Query as it is pre-compiled

• SP can be used to execute complex logic and calculations

• Query is used to retrieve data from a database

• SP can be used to improve database security by granting access to only specific procedures

• Query can be used to filter, sort and group data