IDFC FIRST Bank Interview Questions and Answers

Singleton design pattern ensures a class has only one instance and provides a global point of access to it.

• Used when only one instance of a class is needed throughout the system

• Provides a global access point to the instance

• Implemented by creating a static method to return the same instance each time it is called

Micro service architecture offers scalability, flexibility, and resilience for modern applications.

• Allows for independent development and deployment of services

• Enables easier scaling of individual components

• Improves fault isolation and resilience

• Facilitates technology diversity within the system

• Enhances agility and speed of development

• Example: Netflix, Amazon, Uber

HashMap is not thread-safe, while ConcurrentHashMap allows multiple threads to read and write concurrently.

• HashMap is not synchronized and not thread-safe, while ConcurrentHashMap is synchronized and thread-safe.

• ConcurrentHashMap allows multiple threads to read and write concurrently without any external synchronization, while HashMap requires external synchronization for concurrent access.

• ConcurrentHashMap achieves higher concurrency by dividing the map into segments, allowi...read more

List is an ordered collection of elements with duplicates allowed, while set is an unordered collection of unique elements.

• List maintains the order of elements, while set does not guarantee any specific order.

• List allows duplicate elements, while set does not allow duplicates.

• Example: List - [1, 2, 3, 1], Set - {1, 2, 3}

Activity and Fragment have different life cycles in Android development.

• Activity life cycle includes methods like onCreate, onStart, onResume, onPause, onStop, onDestroy.

• Fragment life cycle includes methods like onAttach, onCreate, onCreateView, onActivityCreated, onStart, onResume, onPause, onStop, onDestroyView, onDestroy, onDetach.

• Fragments can be added or removed dynamically during the activity life cycle.

• Fragments have their own view hierarchy and can be reused in multip...read more

Dependency injection is a design pattern in which components are given their dependencies rather than creating them internally.

• Allows for easier testing by mocking dependencies

• Promotes loose coupling between components

• Improves code reusability and maintainability

• Examples: Constructor injection, Setter injection, Interface injection