Pentaco Automation Interview Questions and Answers

JavaScript is synchronous because it executes code line by line and waits for each line to finish before moving on.

• JavaScript is single-threaded, meaning it can only execute one task at a time.

• Code is executed in the order it appears in the program.

• If a line of code takes a long time to execute, it can block other code from running.

• Asynchronous programming can be used to avoid blocking code and improve performance.

Call for roadside assistance, assess the situation, and ensure the safety of passengers.

• Call for roadside assistance or a tow truck

• Assess the situation and location of the breakdown

• Ensure the safety of passengers by moving them to a safe location

• Communicate with passengers about the situation and estimated time for help to arrive

Virtual DOM is a lightweight copy of the actual DOM that helps in efficient rendering of web pages.

• Virtual DOM is a concept used in ReactJS.

• It is a lightweight copy of the actual DOM.

• It helps in efficient rendering of web pages by minimizing the number of updates to the actual DOM.

• When there is a change in the state of a component, the virtual DOM is updated instead of the actual DOM.

• The virtual DOM then calculates the difference between the previous and updated state and upd...read more

useMemo is used to memoize a value, while useCallback is used to memoize a function.

• useMemo is used to optimize expensive calculations by caching the result

• useCallback is used to optimize expensive function creation by caching the function instance

• useMemo returns a memoized value, while useCallback returns a memoized function

• useMemo is used for any value that can be computed, while useCallback is used for functions that are passed as props to child components

Props are used to pass data from parent to child components, while Redux state is a global state management system.

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

• Redux state can be modified using actions and reducers.

• Props are passed down the component tree, while Redux state is accessible from any component.

• Props are used for small-scale data sharing, while Redux is used for larger-scale state management.

• Example: Passing a user's name as a prop to a child ...read more