Haryana Police Interview Questions and Answers

React props are used to pass data from parent to child components in React applications.

• Props are read-only and cannot be modified by the child component

• Props are passed down from parent to child components

• Props can be accessed using this.props in class components or props in functional components

React state is used to store and manage data within a component.

• State is used to store data that can change over time within a component

• State can be initialized in the constructor using this.state

• State can be updated using this.setState() method

• State changes trigger re-rendering of the component

Redux is a predictable state container for JavaScript apps, commonly used with React for managing application state.

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

• It uses a single immutable state tree which can only be changed by emitting actions

• Reducers are pure functions that specify how the state changes in response to actions

• Redux is commonly used with React to manage the state of components

Reading a file in Node.js involves using the 'fs' module to open and read the contents of the file.

• Use the 'fs' module's 'readFile' method to read the contents of a file asynchronously.

• Pass the file path and encoding as parameters to the 'readFile' method.

• Handle the file contents in the callback function provided to the 'readFile' method.

Creating CRUD APIs for sample data in a MERN stack application

• Create a POST API to add new data

• Create a GET API to retrieve all data

• Create a GET API to retrieve data by ID

• Create a PUT API to update data by ID

• Create a DELETE API to delete data by ID

I used React.js as the framework in my last project.

• React.js is a popular JavaScript library for building user interfaces.

• It allows for the creation of reusable UI components.

• React.js uses a virtual DOM for efficient rendering.

• Example: I used React.js to build a dynamic dashboard for tracking sales data.

Framework structure refers to the organization of code, libraries, and tools used in automation testing.

• Framework structure typically includes folders for test scripts, test data, configuration files, and reusable components.

• It also involves defining the hierarchy of test cases, setting up test suites, and implementing reporting mechanisms.

• Common types of frameworks include data-driven, keyword-driven, and hybrid frameworks.

• Example: In a data-driven framework, test data is se...read more