How do I increment i in useState?

I have been struggling for hours and couldn’t figuring out how to increment i using useState([]). I know useState([]) is an asynchronous function, and I don’t know how to increment i properly to give unique keys to each Text Here is my code – import React, { Component, useState, useEffect } from "react"; import {… Read More How do I increment i in useState?

Why useState provided state is not getting updated in some particular scenarios?

I have been through many similar QnAs on StackOverflow but I am still confused about why it does not work for me. I understand that state update is not synchronous. Also I am not performing any DOM manipulation. The full working demo here which demonstrates the issue – https://codesandbox.io/s/falling-pine-kljujf?file=/src/Tabs.js In this example I am rendering… Read More Why useState provided state is not getting updated in some particular scenarios?

Convert DidMount/DidUnmount from react class component to functional component

I am writing a simple timer app in react. The timer is not owned by the react component, but will be shared across several timer components. As part of component mounting, I register the react component with my universal timer, and it updates the component with ‘ticks’. My expectation is that when the component is… Read More Convert DidMount/DidUnmount from react class component to functional component

Prevent child rerenders when parent state is changed?

This is a simplified version of my problem https://codesandbox.io/s/withered-night-6jbgft import React, { useState, useCallback } from "react"; import "./styles.css"; const Box = React.memo(({ c, i, handleClick }) => { return ( <div className="box" style={{ background: c }} onClick={() => handleClick(i)} ></div> ); }); export default function App() { const COUNT_BOXES = 250; const [colour, setColour]… Read More Prevent child rerenders when parent state is changed?

update multiple objects in state with single function

I have 3 different Accordions that a single state controls their open and close state like so: const [accordionOpen, setAccordionOpen] = useState({ countryOfOriginAccordion: true, schoolAccordion: false, areaOfStudyAccordion: false, }); ideally, I am setting each state with their own function like this: setAccordionOpen((previousState) => ({ …previousState, schoolAccordion: !accordionOpen.schoolAccordion, })) I want to use a single function… Read More update multiple objects in state with single function

sending updated value to API with useState

I have an API that gets count. whenever user clicks on IconButton I must send the count to my server, but it always sends previous value. like if count is 1 it sends 0. const { fetchCalculatedService, response } = useCalcService(); const [count, setCount] = React.useState(0); <IconButton color="success" disabled={!selectInsurance} onClick={() => { setCount((prev) => prev… Read More sending updated value to API with useState

Undefined state using async await function with axios in React App

I am creating a basic weather app that fetches data from the Openweathermap API and displays it on the page. I don’t get why the console.log(data) is showing undefined in my console? const [data, setData] = useState() useEffect(() => { const fetchData = async () => { const res = await axios.get(url) setData(res.data) console.log(data) }… Read More Undefined state using async await function with axios in React App