Infosys Technology Analyst Interview Questions, Process, and Tips

Abstract class is a class that cannot be instantiated and Interface is a blueprint of a class.

• 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.

• Example of Abstract class: Animal (abstract method: makeSound())

• Example

A singleton class is a class that can only have one instance created at a time.

• Singleton classes are often used in situations where there should only be one instance of a class, such as a database connection or a configuration manager.

• The class typically has a private constructor to prevent multiple instances from being created.

• The instance of the class is usually accessed through a static method or property.

• Example: J...read more

Transactional in Hibernate refers to the management of database transactions.

• Hibernate provides transaction management through the use of the Transaction interface.

• Transactions can be managed programmatically or declaratively using annotations.

• Transactional behavior can be customized using isolation levels and propagation settings.

• Example: @Transactional annotation can be used to mark a method as transactional.

• Example:...read more

Explanation of terms in public static void main (string args[])

• public: Access modifier indicating that the method can be accessed from anywhere

• static: Keyword indicating that the method belongs to the class and not to an instance of the class

• void: Return type indicating that the method does not return any value

• main: Method name, the entry point of the program

• string[] args: Parameter of the method, an array of strings t

A static method is a method that belongs to a class rather than an instance of the class.

• Static methods can be called without creating an instance of the class.

• They are often used for utility functions that don't require access to instance variables.

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

• Example: Math.max() is a static method that returns the maximum of two numbers.

Design patterns are reusable solutions to common software problems. Singleton is a design pattern that restricts the instantiation of a class to one object.

• Design patterns are proven solutions to recurring software problems

• Singleton pattern ensures only one instance of a class is created

• Singleton pattern is useful in scenarios where only one instance of a class is required

• Other design patterns include Factory, Observer

Finalize is used to perform any necessary cleanup operations before an object is destroyed, while dispose is used to release unmanaged resources.

• Finalize is a method that is automatically called by the garbage collector when an object is no longer in use.

• Dispose is a method that must be called explicitly to release unmanaged resources.

• Finalize is not guaranteed to be called, while Dispose is.

• Examples of unmanaged resou...read more

Interface and abstract class examples in current project

• Interface defines a contract for classes to implement

• Abstract class provides partial implementation and can't be instantiated

• Example: Interface - IPaymentGateway with methods like processPayment()

• Example: Abstract class - Payment with abstract method processPayment() and concrete method logTransaction()

Agile and waterfall are two project management methodologies. Agile is iterative and flexible, while waterfall is linear and rigid.

• Agile focuses on delivering working software in short iterations, while waterfall follows a sequential process.

• Agile encourages collaboration and adaptability, while waterfall relies on detailed planning and documentation.

• Agile allows for changes and feedback throughout the project, while w...read more

Program to sort an array in descending order with minimum lines of code

• Use built-in sort function with reverse parameter

• Alternatively, use a lambda function with sorted() method

• Both methods can be implemented in one line of code

Events and delegates are used for implementing the observer pattern in C#.

• Events are used to notify subscribers when something happens.

• Delegates are used to define the signature of the event handler method.

• Events can have multiple subscribers, and subscribers can unsubscribe.

• Example: Button click event with multiple event handlers.

• Example: Custom event for notifying when a file is saved.

• Example: Using delegates to pass

Parameterised constructor executes first if called explicitly, else default constructor.

• If an object is created without any arguments, default constructor executes first.

• If an object is created with arguments, parameterised constructor executes first.

• Explicitly calling parameterised constructor will execute it first.