ilxanlar

import React, { useState, useEffect } from 'react'

function Example() {
  const [width, setWidth] = useState(...)

  useEffect(() => {
    function handleResize(event) {
      // Calculate window width...
      setWidth(...)
    }

ilxanlar

import React, { useState, useEffect } from 'react'

function FriendStatus({ friendId }) {
  const [isOnline, setIsOnline] = useState(null)

  useEffect(() => {
    function handleStatusChange(status) {
      setIsOnline(status.isOnline)
    }

ilxanlar

import React, { useState, useEffect } from 'react'

function Example() {
  const [width, setWidth] = useState(...)

  useEffect(() => {
    function handleResize(event) {
      // Calculate window width...
      setWidth(...)
    }

ilxanlar

import React, { useState, useEffect } from 'react'

function Example() {
  const [count, setCount] = useState(0)

  useEffect(() => {
    document.title = `You clicked ${count} times`
  }, [count]) // Pass [count] as dependencies

  return (

ilxanlar

import React, { useState, useEffect } from 'react'

function FriendStatus({ friendId }) {
  const [isOnline, setIsOnline] = useState(null)

  useEffect(() => {
    function handleStatusChange(status) {
      setIsOnline(status.isOnline)
    }

ilxanlar

import React, { useState, useEffect } from 'react'

function Example() {
  // Read initial count from localStorage
  const [count, setCount] = useState(localStorage.getItem('count') || 0)

  // Similar to componentDidMount and componentDidUpdate:
  useEffect(() => {
    // Update the document title using the browser API
    document.title = `You clicked ${count} times`

ilxanlar

import React, { useState, useEffect } from 'react'

function Example() {
  // Read initial count from localStorage
  const [count, setCount] = useState(localStorage.getItem('count') || 0)

  // Similar to componentDidMount and componentDidUpdate:
  useEffect(() => {
    // Update the document title using the browser API
    document.title = `You clicked ${count} times`

ilxanlar

import React, { useState, useEffect } from 'react'

function Example() {
  const [count, setCount] = useState(0)

  // Similar to componentDidMount and componentDidUpdate:
  useEffect(() => {
    // Update the document title using the browser API
    document.title = `You clicked ${count} times`
  })

ilxanlar

import { useEffect, useRef, useState } from 'react'

export default function useNow(interval = 1000) {
  const [date, setDate] = useState(() => (new Date()))

  const intervalRef = useRef()

  useEffect(() => {
    intervalRef.current = setInterval(() => {
      setDate(new Date())

ilxanlar

import { useEffect } from 'react'

export default function useOnClickOutside(ref, callback) {
  useEffect(() => {
    const listener = (event) => {
      if (ref && ref.current && !ref.current.contains(event.target)) {
        callback(event)
      }
    }