Cognizant Software Engineer Interview Questions and Answers for Experienced

OOP (Object-Oriented Programming) is a programming paradigm based on objects and classes to structure software design.

• Encapsulation: Bundling data and methods that operate on the data within one unit (e.g., a class).

• Inheritance: Mechanism where a new class derives properties and behavior from an existing class (e.g., a 'Dog' class inheriting from an 'Animal' class).

• Polymorphism: Ability to present the same interfa...read more

Inheritance is a fundamental OOP concept allowing a class to inherit properties and methods from another class.

• Promotes code reusability by allowing new classes to use existing code.

• Supports method overriding, enabling a subclass to provide a specific implementation.

• Example: A 'Dog' class can inherit from an 'Animal' class, gaining its properties like 'legs' and methods like 'eat'.

• Facilitates a hierarchical classi...read more

OOP in Java is a programming paradigm based on objects, encapsulation, inheritance, and polymorphism for better code organization.

• Encapsulation: Bundling data and methods that operate on the data within one unit (class). Example: private variables with public getters/setters.

• Inheritance: Mechanism where one class inherits properties and behaviors from another. Example: class Dog extends Animal.

• Polymorphism: Abilit...read more

The Singleton design pattern restricts a class to a single instance and provides a global access point to that instance.

• Ensures a class has only one instance.

• Provides a global point of access to that instance.

• Useful for managing shared resources, like database connections.

• Implemented using private constructors and static methods.

• Example in Java: public class Singleton { private static Singleton instance; private S...read more

.NET is a software development framework created by Microsoft, enabling developers to build applications for various platforms.

• .NET Framework: The original version, primarily for Windows applications, supports languages like C# and VB.NET.

• .NET Core: A cross-platform, open-source version of .NET that allows developers to build applications for Windows, macOS, and Linux.

• .NET 5 and later: Unified platform that combin...read more

Lookup activity is used in Azure Data Factory to retrieve a single row from a dataset based on a specified key.

• Lookup activity is used to retrieve data from a database or file system in Azure Data Factory.

• It can be used to perform lookups on tables, views, or files.

• The lookup activity requires a dataset and a query to specify the data to retrieve.

• It is commonly used in data integration pipelines to fetch reference...read more