Avegen Health Mobile Developer Interview Questions, Process, and Tips

Virtual DOM is a lightweight copy of the actual DOM, used by React to efficiently update and render components.

• Virtual DOM is a concept in React that improves performance by minimizing direct manipulation of the actual DOM.

• It is a lightweight copy of the actual DOM tree, stored in memory.

• React uses the Virtual DOM to determine the most efficient way to update the actual DOM.

• When changes are made to the Virtual DOM, Rea...read more

React component lifecycle includes mounting, updating, and unmounting phases.

• Mounting phase: constructor() -> getDerivedStateFromProps() -> render() -> componentDidMount()

• Updating phase: getDerivedStateFromProps() -> shouldComponentUpdate() -> render() -> getSnapshotBeforeUpdate() -> componentDidUpdate()

• Unmounting phase: componentWillUnmount()

• Examples: constructor() initializes state, componentDidMount() fetches data, ...read more

React has three main stages in its lifecycle: Mounting, Updating, and Unmounting.

• Mounting: when a component is being created and inserted into the DOM

• Updating: when a component is being re-rendered due to changes in props or state

• Unmounting: when a component is being removed from the DOM

Event loop is a mechanism that allows JavaScript to perform non-blocking I/O operations.

• Event loop is responsible for handling asynchronous callbacks in JavaScript.

• It continuously checks the call stack and the task queue for any pending tasks.

• If the call stack is empty, it picks up the first task from the task queue and pushes it onto the call stack.

• It then executes the task and repeats the process until there are no m...read more

Yes, state is mutable in Redux.

• State in Redux is mutable, but it should not be directly mutated.

• Changes to state should be made through pure functions called reducers.

• The immutability of state is important for predictable and efficient updates.

• Examples of state mutation include using the 'push' method on an array or directly modifying an object property.