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To create a sleep function in React: Define a function that takes a number of milliseconds as a parameter. The function should return a Promise that is resolved after the provided number of milliseconds....

Setting the CSS visibility property to hidden in React: Store a boolean value in the state indicating whether the element should be visible. Conditionally set the visibility property in the element's style attribute. For example, style={{visibility: i...

To update state when props change in React: pass props as dependencies to the useEffect hook. Every time props change, the logic in useEffect will re-run....

To update an array of object state in React: Use the map() method to iterate over the array. In each iteration, check if a condition is met. Update the properties of the objects that meet the condition....

To resolve "Uncaught ReferenceError: process is not defined" in React, you need to open a terminal in the root directory of your project and update the version of the react-scripts package by running npm install react-scripts@latest and reinstall depe...

Conditionally set the CSS `display` property to none in React: Store a boolean value in the state indicating whether the element should be displayed. Conditionally set the display property in the element's `style` attribute. For example, style={{displ...

Template literals are used in React for string interpolation, for example div className={text-white ${myClass}} . Template literals are delimited by backticks and allow us to embed variables and expressions using the dollar sign and curly brace ${expr...

In React, we use square brackets to get the first element of an array, for example, const first = arr[0]; . The array element with index 0 is the first element in the array. If the array is empty, undefined is returned. import {useState} from react ; ...

To get the mouse position in React: Set the `onMouseMove` property on the element or add an event listener on the window object. Provide an event handler function. Access the relevant properties of the event object....

To create an input field in React.js that only contains numbers: Set the input field's type to text . Add an onChange event handler that removes all non-numeric values ​​. Save the input value in a state variable. import { useState } from reactjs...

In React, we use the String() function to render boolean values ​​in JSX, for example, h2{string(bool1)}/h2 . By default, boolean values ​​don’t render anything in React, so we have to convert the value to a string in order to render it. exp...

To delete query parameters using React Router: Use the useSearchParams hook to get the search parameters for the current location. Use the delete() method to delete each query parameter, such as searchParams.delete('q'). To update the search parameter...

To check if a browser tab has focus using React: Add event listeners for the focus and blur events. If the focus event is fired, the tab has focus. If the blur event is fired, the tab loses focus. import {useE...

To detect when the Esc key is pressed in React.js: Add a keydown event listener to the document element. When the user presses a key, check if the key is Esc. If the key pressed is Escape, call a function or run some logic. import {u...

To find an object in an array in React: Call the find() method on the array and pass it a function. The function should return an equality check for the relevant properties. The find() method returns the first value in the array that satisfies the con...