Frontend

Cookie'larning qanday sozlamalari mavjud (httpOnly, secure, expires, domain, path)?

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IT One

const obj = [{ value: 1, elems: [ { value: 2, elems: [ { value: 3 }, { value: 6 }, ... ] }, { value: 4, elems: [ { value: 5, elems: [ { value: 6 }, ... ]} ] } ] }] ------------- setTimeout(() => { console.log(1); }, 0); const p = new Promise(resolve => { console.log(2); resolve(); }); p.then(() => { console.log(3) }).then(() => { console.log(4); }); console.log(5);

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IT One

JavaScript'dagi Map va Set kolleksiyalari haqida gapir — ular haqida nima bilasiz?

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IT One

let/const va var ning ko'lamlari qanday? var, let, const dan tashqari boshqa biron bir o'zgaruvchi e'lon qilish usuli bormi?

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IT One

import React, { useState, useEffect, useRef, useContext, useReducer, useMemo } from 'react'; export default Effects = () => { const [count, setCount] = useState(0); useLayoutEffect(() => console.log("har bir render 1")); console.log("har bir render 2"); useEffect(() => console.log("har bir render 3")); return ( <> <button onClick={() => setCount((prevProps) => ++prevProps)}> Арттыру </button> </> ) }

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IT One

Reactda render nima ekanligini qanday tushunasiz? Nima uchun bo'lishi mumkin?

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IT One

const func = obj.sayHi() const boundFuns = func.bind(obj) boundFuns() ------------------- const submit = (el) => () => { log(el); } arr.map(el => <button onClick={submit(el)}/>) const param = useMemo(() => a + b) return <Child value={param} />

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IT One

getParam funktsiyasini shunday tipikla, shunda TypeScript obyekt ichida mavjud bo'lgan xususiyatlarni avtomatik ravishda ko'rsatadi. Tipiklashni shunday qilki, massivlarni o'tkazib yuborish mumkin bo'lmasin.

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IT One

WeakMap nima?

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IT One

const { foo: bar, bar: foo } = { foo: 1, bar: 2 } console.log(bar) // console.log(foo) //

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IT One

Analitik bo'lmagan holda, vazifani o'zingiz tushunishingiz kerak bo'lgan ish tajribangiz bo'ldimi?

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IT One

React qanday qilib propslarni solishtiradi? Qavatli solishtirish qanday ishlaydi?

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IT One

Agar ota komponent yangi massivni props sifatida yuborsa, ekraningizda yangi ma'lumotlarni ko'rasizmi yoki eski? Nima uchun?

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IT One

const Effects = () => { const [count, setCount] = useState(0); useLayoutEffect(() => console.log("har bir render 1")); console.log("har bir render 2"); useEffect(() => console.log("har bir render 3")); return ( <> {count} <button onClick={() => setCount((prevProps) => ++prevProps)}> Ko'paytirish </button> </> ); }; export default Effects; // 1 render: // Bosgandan keyin: const Effects = () => { const [count, setCount] = useState(0); const [number, setNumber] = useState(0); useEffect(() => { console.log(count); return () => { console.log(count); }; }); return ( <> {count} <button onClick={() => setCount((prevProps) => ++prevProps)}> Ko'paytirish </button> </> ); }; export default Effects; // 1 render: // 2 1 3 // Bosgandan keyin: // 2 1 3 // nullga qaytarish: // 2 1 3 // // 1: 1, 0 // +: 1, 2 // ++: 2, 2

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IT One

let obj = { a: 1 }; let array = [obj]; obj = null; console.log(obj); // console.log(array); //

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const S = { id: 1, name: "Ivan", age: "39", tel: [phone] }; function getParam(obj, key) { return obj[key]; } getParam(S, "tel"); getParam(S, "job");

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IT One

import { useState, useRef, useEffect } from "react"; const useDebugRender = ({props}) => { const prevProp = useRef(props) useEffect(() => { }, []) } const ParentComponent = () => { const [random, setRandom] = useState(0); // Prop sifatida bolaga komponentga uzatiladi const [text, setText] = useState(""); // Prop sifatida bolaga komponentga uzatiladi const createRandom = () => setRandom(Math.floor(Math.random() * 100)); const onTextChange = (e) => setText(e.target.value); const [count, setCount] = useState(0); const incrementCount = () => setCount((prev) => prev + 1); // Bu funksiya Prop sifatida bolaga komponentga uzatiladi return ( <> <Count: {count} /> <input type="text" onChange={onTextChange} /> <button onClick={createRandom}>Tasodifiy yaratish</button> <div> <ChildComponent random={random} text={text} incrementCount={incrementCount} /> </div> </> ); }; export default ParentComponent;

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IT One

useRef nima uchun kerak? Uning qanday qo'llanilishi bor?

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IT One

const submit = useCallback((el) => () => { log(el); }, []); arr.map(el => <button onClick={submit(el)} />) arr.map(el => <SomeComp key={} onClick={() => submit(el)} />) const param = useMemo(() => ({c: a + b}), [a,b]) return <Child value={param} /> Child = React.memo(() => {})

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await p1, await p2 va Promise.all([p1, p2]) o'rtasidagi farq nima?

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IT One