This repository is intended to be a comprehensive resource for React-Native interview questions and answers. Whether you're a job seeker looking to prepare for an interview, or an interviewer looking for a list of questions to ask candidates, this repository should have you covered.
To ensure that this repository remains a high-quality resource, please keep the following guidelines in mind when contributing:
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Provide context for each question. When adding a question, make sure to provide some background information on the concept or feature being discussed. This will help users understand the relevance of the question and why it is important to know.
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React-Native is an open-source framework for building native mobile applications using JavaScript and React. It was created by Facebook and is used by many popular apps, such as Instagram, Facebook, and Airbnb. React-Native allows developers to write code once and use it across multiple platforms, including iOS, Android, and web.
Some of the major features of React-Native include:
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Hot reloading: With hot reloading, changes to the code are reflected immediately in the app, making it easier and faster to develop and debug.
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Code reuse: React-Native allows developers to write code once and use it across multiple platforms, which can save time and reduce development costs.
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Native performance: React-Native apps are built using native components, which means they have performance characteristics similar to those of apps built using native languages.
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Third-party library support: React-Native has a large and active community, which has created many third-party libraries and tools to help developers build and maintain their apps.
JSX is a syntax extension for JavaScript that allows developers to write HTML-like code in their JavaScript files. It is used in React to describe what the user interface of a component should look like. JSX makes it easier to write and read code by allowing developers to write HTML-like syntax, which is then compiled to JavaScript.
React is a JavaScript library that is used for building user interfaces. It was originally developed by Facebook and is now maintained by a community of developers. React allows developers to create reusable UI components and manage the state of those components efficiently.
React-Native, on the other hand, is a framework that allows developers to build mobile applications using React. It allows developers to use the same design principles and programming concepts that they use in React to build native mobile apps for iOS and Android.
The Virtual DOM (Document Object Model) is a programming concept used in React-Native that represents the user interface of an application as a virtual tree structure. This tree structure is stored in memory and is used by React to update the UI efficiently.
When an application's state changes, React updates the virtual tree and then compares it to the previous version of the tree. The changes are then applied to the real DOM, which is the actual web page or mobile app interface that the user sees.
The use of the Virtual DOM allows React to update the UI in a very efficient manner. Instead of updating the entire UI every time there is a change, React only updates the parts of the UI that have actually changed.
In React-Native, both state and props are used to manage data in a component, but they have different purposes. State is used for data that is internal to the component and can change over time. It should only be modified using the setState() method. Props, on the other hand, are used to pass data from a parent component to a child component. They are read-only and should not be modified within the child component. To summarize, state is managed internally by a component while props are passed down from its parent.
Handling user input in React-Native involves adding event listeners to components and updating state accordingly. For example, you can add an onChangeText event listener to a text input component to capture user input and update the state of the component. You can also use other event listeners like onPress for buttons or onSubmitEditing for text inputs to handle user interactions. Additionally, you can use various third-party libraries like react-native-gesture-handler to handle more complex user interactions like swipes and pinches.
Redux is a popular state management library used in React-Native applications. It provides a centralized store to manage state, making it easier to manage complex data flows and maintain a consistent state throughout the application. Redux can be particularly useful in large applications with many components that share data. With Redux, state can be easily accessed and updated from any component in the application, making it easier to maintain a predictable state and reduce bugs caused by state management issues. However, it is important to note that using Redux can add additional complexity to a project and may not be necessary for smaller applications.
Both Flexbox and Grid are layout systems that are used in React-Native to arrange and position UI elements on the screen.
Flexbox is a one-dimensional layout system that arranges UI elements along a single axis, either horizontally or vertically. It is particularly useful for creating responsive layouts that can adapt to different screen sizes.
Grid, on the other hand, is a two-dimensional layout system that arranges UI elements in rows and columns. It is useful for creating more complex UI layouts, particularly those that require a more structured grid-like layout.
The choice between Flexbox and Grid depends on the specific requirements of the UI layout. In general, Flexbox is best for simple, responsive layouts, while Grid is better suited for more complex, structured layouts.