10+ Saha Infratech Interview Questions and Answers

I am currently working on a web application for a retail company using React, Node.js, and MongoDB.

• Developing a responsive UI using React and Redux

• Implementing server-side logic using Node.js and Express

• Storing and retrieving data using MongoDB

• Integrating third-party APIs for payment processing and shipping

• Writing automated tests using Jest and Enzyme

Dependency Injection is a design pattern used to remove hard-coded dependencies and make code more flexible and testable.

• Dependency Injection is implemented by injecting the required dependencies into a class rather than creating them within the class.

• This can be achieved through constructor injection, setter injection, or interface injection.

• For example, in Java, Spring Framework provides a powerful dependency injection mechanism through its @Autowired annotation.

• Dependency ...read more

Yes, authentication is implemented using OAuth 2.0 protocol.

• OAuth 2.0 protocol is used for authentication.

• Access tokens are issued to authorized clients.

• Refresh tokens are used to obtain new access tokens.

• Authentication is required for all API endpoints.

Ref and out are keywords used in C# to pass arguments by reference instead of value.

• Ref and out are used to pass arguments by reference instead of value

• Ref keyword is used to pass a reference of the variable to the method

• Out keyword is used to pass a reference of the variable to the method and requires the variable to be initialized before use

• Ref keyword can be used to modify the value of the variable passed as an argument

• Out keyword is used when the method needs to return mu...read more

Interfaces define contracts for behavior while abstract classes provide partial implementation.

• Interfaces cannot have implementation while abstract classes can have partial implementation.

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

• Interfaces are used for loose coupling while abstract classes are used for code reuse.

• Example: An interface 'Drawable' can define a method 'draw' which any class implementing it must define. An abstract cl...read more

Value types hold the data directly, while reference types hold a reference to the data.

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

• String is a reference type in .NET.

• Value types include int, float, and bool.

• Reference types include arrays, classes, and interfaces.

Self Join is a way to join a table with itself using aliases.

• It is useful when we need to compare records within the same table.

• It requires the use of aliases to differentiate between the two instances of the same table.

• Example: SELECT a.name, b.name FROM employees a, employees b WHERE a.manager_id = b.employee_id;

Action Filters are attributes that can be applied to controller actions to perform pre/post processing.

• Action Filters are used to modify the behavior of controller actions.

• They can be used to perform authentication, logging, caching, etc.

• Action Filters can be applied globally or to specific actions.

• Examples include [Authorize] for authentication and [OutputCache] for caching.

• Action Filters can also be created by the developer to perform custom processing.

Interfaces are a way to define a contract between two objects, specifying the methods and properties that one object must implement.

• Interfaces allow for loose coupling between objects, making it easier to change the implementation of one object without affecting others.

• They promote code reusability by allowing multiple objects to implement the same interface.

• Interfaces can be used to create mock objects for testing purposes.

• Examples of interfaces in Java include Comparable, R...read more

Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity.

• Normalization involves breaking down a table into smaller tables and defining relationships between them.

• There are different levels of normalization, with each level reducing redundancy and improving data integrity further.

• Normalization helps to prevent data inconsistencies and anomalies, and makes it easier to maintain and update the database.

• Examples of normalizatio...read more

Delegates are a type-safe function pointer used to encapsulate a method.

• Delegates allow methods to be passed as parameters to other methods.

• They can be used to implement callbacks and event handlers.

• Delegates can be chained together to create a pipeline of method calls.

• They are commonly used in .NET framework for event handling and LINQ queries.

Shallow copy creates a new object with same values as original, but references the same memory locations.

• Shallow copy only copies the top-level object, not the nested objects.

• Changes made to the original object will reflect in the copied object.

• Use MemberwiseClone() method to create shallow copy of an object.

• Example: int[] arr1 = {1, 2, 3}; int[] arr2 = arr1.Clone() as int[]; arr2[0] = 4; Console.WriteLine(arr1[0]); // Output: 1

Overriding is when a subclass provides its own implementation of a method from the superclass, while overloading is when a class has multiple methods with the same name but different parameters.

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

• Overloading is used to define multiple methods with the same name but different parameters in a class.

• Overriding is used for runtime polymorphism, while overloadi...read more

IEnumerable is in-memory collection while IQueryable is a queryable data source.

• IEnumerable is used for querying data from in-memory collections like List, Array, etc.

• IQueryable is used for querying data from a data source like a database.

• IEnumerable executes the query on the client-side while IQueryable executes the query on the server-side.

• IQueryable is more efficient when working with large datasets as it allows for filtering and sorting on the server-side.

• Example: var lis...read more