Turing Senior Software Engineer Interview Questions and Answers

useRef hook is used to persist a mutable value across renders without causing a re-render.

• Used to store mutable values that do not trigger re-renders.

• Commonly used for accessing DOM elements or storing previous values.

• Does not cause a re-render when the value changes.

Use memoization, virtual DOM, and shouldComponentUpdate to avoid unnecessary rerenders and improve performance.

• Implement memoization to store the result of expensive function calls and avoid recalculating them.

• Use virtual DOM to efficiently update only the parts of the UI that have changed.

• Override shouldComponentUpdate to prevent unnecessary rerenders by comparing current and next props/state.

Callbacks, Promises, async await are asynchronous programming concepts in JavaScript.

• Callbacks are functions passed as arguments to another function to be executed later.

• Promises are objects representing the eventual completion or failure of an asynchronous operation.

• async await is a syntax for writing asynchronous code that looks synchronous, making it easier to read and maintain.

• Example: Using a callback to handle th...read more