Niyal Services Interview Questions and Answers

React Hooks are functions that let you use state and other React features without writing a class.

• React Hooks were introduced in React 16.8 to allow functional components to have state and lifecycle methods.

• useState() is a Hook that lets you add state to functional components.

• useEffect() is a Hook that lets you perform side effects in functional components.

• Hooks are more readable and easier to maintain than class components.

• Example: const [count, setCount] = useState(0);

React Redux is a state management library for React applications.

• React Redux helps manage the state of a React application in a predictable way

• It allows for a centralized store to hold the application's state

• Actions are dispatched to update the state, and reducers specify how the state should change

• Selectors can be used to retrieve specific pieces of state from the store

String operations in Python and joins in SQL

• Python has built-in string methods like split(), join(), replace() etc.

• SQL joins are used to combine rows from two or more tables based on a related column

• Types of SQL joins: INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL OUTER JOIN

• String operations in Python can be used to manipulate text data for analysis or processing in SQL

Agile is iterative and flexible, while Waterfall is sequential and rigid.

• Agile involves breaking projects into smaller tasks and adapting to changes quickly.

• Waterfall follows a linear approach with distinct phases like planning, design, development, testing, and deployment.

• I have used Agile methodology in a software development project where requirements were evolving.

• I have used Waterfall methodology in a construction project where the scope was well-defined from the beginni...read more

I would facilitate estimations for a sprint by involving the team in a collaborative process, using techniques like Planning Poker.

• Involve the entire team in the estimation process to ensure buy-in and accuracy

• Use techniques like Planning Poker to facilitate collaborative estimation

• Break down user stories into smaller tasks for more accurate estimations

• Consider historical data and team velocity when making estimations

I have implemented Scrum and Kanban methodologies in previous projects.

• Implemented Scrum framework for daily stand-up meetings, sprint planning, and retrospectives

• Utilized Kanban board for visualizing workflow and tracking progress

• Facilitated regular backlog grooming sessions to prioritize tasks and user stories

To display special characters in a given string and find all permutations of the string.

• Create a function to display special characters in a given string using regex

• Use recursion to find all permutations of the string

• Store the permutations in an array of strings

Use Java code to replace a character in a string.

• Use the replace() method to replace a character in a string.

• Specify the character to be replaced and the character to replace it with.

• Example: String str = "hello"; str = str.replace('e', 'a'); // Output: hallo