Q601. What is a void operator?
The `void` operator evaluates the given expression and then returns `undefined` (i.e, without returning value). The syntax would be as below, ```javascript void expressio...
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Q602. Is that possible to use useImperativeHandle without forwardRef?
**No.** `useImperativeHandle` only works when the component is wrapped in `forwardRef`. It's the combination that allows parent components to use a `ref` on a function co...
Q603. How to set the cursor to wait?
The cursor can be set to wait in JavaScript by using the property `cursor`. Let's perform this behavior on page load using the below function. ```javascript function myFu...
Q604. How is useMemo different from useCallback?
The following table compares both useMemo and useCallback: | Feature | `useMemo` | `useCallback` | | --- | --- | --- | | **Purpose** | Memoizes the **result of a computat...
Q605. How do you create an infinite loop?
You can create infinite loops using for and while loops without using any expressions. The for loop construct or syntax is better approach in terms of ESLint and code opt...
Q606. Does useMemo prevent re-rendering of child components?
The `useMemo` hook **does not directly prevent re-rendering of child components**. Its main purpose is to memoize the result of an expensive computation so that it doesn’...
Q607. Why do you need to avoid with statement?
JavaScript's with statement was intended to provide a shorthand for writing recurring accesses to objects. So it can help reduce file size by reducing the need to repeat ...
Q608. What is `useCallback` and why is it used?
The `useCallback` is a React Hook used to memoize **function definitions** between renders. It returns the same function reference unless its dependencies change. This is...
Q609. What is the output of the following for loops?
```javascript for (var i = 0; i < 4; i++) { // global scope setTimeout(() => console.log(i)); } for (let i = 0; i < 4; i++) { // block scope setTimeout(() => console.log(...
Q610. What are Custom React Hooks, and How Can You Develop One?
**Custom Hooks** in React are JavaScript functions that allow you to **extract and reuse component logic** using React’s built-in Hooks like `useState`, `useEffect`, etc....