Dew Solutions React Native Developer Interview Questions and Answers

Enums in TypeScript are a way to define a set of named constants. Shallow copy only copies the reference, while deep copy creates a new object. Virtual DOM is a lightweight copy of the actual DOM. Closures are functions that have access to their own scope and the scope of their containing function.

• Enums in TypeScript are used to define a set of named constants. For example, enum Color { Red, Green, Blue }

• Shallow copy c...read more

Life cycle methods are special methods in class components that allow developers to run code at specific points in the component's life cycle.

• componentDidMount() is called after the component has been rendered to the DOM.

• componentDidUpdate() is called after the component's state or props have been updated.

• componentWillUnmount() is called before the component is removed from the DOM.

FlatList is optimized for rendering large lists efficiently by only rendering the items that are currently visible, while ScrollView renders all of its children at once.

• FlatList is more performant for long lists as it only renders the items that are currently visible on the screen.

• ScrollView renders all of its children at once, which can lead to performance issues with large datasets.

• FlatList supports key extraction fo...read more

Create a CRUD app to render, edit, delete, and sort a list of objects in a table.

• Create a React component to render a table with data from the array of objects.

• Implement functions for editing and deleting objects from the list.

• Add functionality to sort the list based on object properties.

• Use state and props to manage data and re-render the table when changes occur.

rem, em, px are units of measurement in CSS. useEffect is a React hook for side effects. Hooks are used for stateful logic in functional components.

• rem: relative to the font-size of the root element (html). Example: 1rem = 16px

• em: relative to the font-size of the element. Example: 2em = 32px if the font-size of the element is 16px

• px: fixed-size units. Example: font-size: 14px

• useEffect: React hook used for side effects ...read more

Activity life cycle is a crucial concept in Android development. Factorial and Fibonacci series are common mathematical problems. lateinit var and lazy are used for initializing variables. Var and val are used for declaring variables.

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

• Factorial is the product of all positive integers up to a given number. Example: 5! = 5*4*...read more