How to replace Component lifecycle with useEffect hook in React?

Before React 16.8, we were forced to use class based component to have access in component lifecycle. And now with Hooks, we are now able to use functional component for state management, data fetching etc. We can now replace component lifecycle like componentDidMountcomponentDidUpdate and componentWillUnmount with useEffect in our React component.

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1. componentDidMount

The componentDidMount() method runs after the component output has been rendered to the DOM. This is a good place to cause side-effects.

// With ccomponentDidMount()
componentDidMount() {
    console.log('Hello World');

// with useEffect()
useEffect(() => {
    console.log('Hello World');
}, [])

If we don’t pass an empty array to useEffect, it will run on every change. Therefore, we must give as second argument an empty array to mimic the componentDidMount behavior. It tells to React that your effect doesn’t depend on any values from props or state, so it never needs to re-run, useEffect will run only once after the component is created.

2. componentDidUpdate

The componentDidUpdate() method is invoked immediately after updating occurs.

// With ccomponentDidUpdate()
componentDidUpdate(prevProps) {
    console.log(`Hello World ${prevProps}`);

// with useEffect()
useEffect(() => {
    console.log('Hello World');
}, [prevProps])

When we pass a value(prevProps) to the array, it tells to useEffect to run only if the value change.

3. componentWillUnmount

The componentWillUnmount() method is called immediately before a component is unmounted and destroyed. It is a good place to do some cleanup works.

// With ccomponentDidUnmount()
componentWillUnmount() {
    console.log('Hello World');

// with useEffect()
useEffect(() => {
    console.log('Hello World');
    return () => {
        console.log('Do some cleanup');
}, [])

By returning an anonymous function with useEffect, it will run before the component unmounting. And the empty array passed as second argument tells to useEffect to run when the component will be mounted or unmounted.


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How to replace Component lifecycle with useEffect hook in React?
Autumn  Blick

Autumn Blick


How native is React Native? | React Native vs Native App Development

If you are undertaking a mobile app development for your start-up or enterprise, you are likely wondering whether to use React Native. As a popular development framework, React Native helps you to develop near-native mobile apps. However, you are probably also wondering how close you can get to a native app by using React Native. How native is React Native?

In the article, we discuss the similarities between native mobile development and development using React Native. We also touch upon where they differ and how to bridge the gaps. Read on.

A brief introduction to React Native

Let’s briefly set the context first. We will briefly touch upon what React Native is and how it differs from earlier hybrid frameworks.

React Native is a popular JavaScript framework that Facebook has created. You can use this open-source framework to code natively rendering Android and iOS mobile apps. You can use it to develop web apps too.

Facebook has developed React Native based on React, its JavaScript library. The first release of React Native came in March 2015. At the time of writing this article, the latest stable release of React Native is 0.62.0, and it was released in March 2020.

Although relatively new, React Native has acquired a high degree of popularity. The “Stack Overflow Developer Survey 2019” report identifies it as the 8th most loved framework. Facebook, Walmart, and Bloomberg are some of the top companies that use React Native.

The popularity of React Native comes from its advantages. Some of its advantages are as follows:

  • Performance: It delivers optimal performance.
  • Cross-platform development: You can develop both Android and iOS apps with it. The reuse of code expedites development and reduces costs.
  • UI design: React Native enables you to design simple and responsive UI for your mobile app.
  • 3rd party plugins: This framework supports 3rd party plugins.
  • Developer community: A vibrant community of developers support React Native.

Why React Native is fundamentally different from earlier hybrid frameworks

Are you wondering whether React Native is just another of those hybrid frameworks like Ionic or Cordova? It’s not! React Native is fundamentally different from these earlier hybrid frameworks.

React Native is very close to native. Consider the following aspects as described on the React Native website:

  • Access to many native platforms features: The primitives of React Native render to native platform UI. This means that your React Native app will use many native platform APIs as native apps would do.
  • Near-native user experience: React Native provides several native components, and these are platform agnostic.
  • The ease of accessing native APIs: React Native uses a declarative UI paradigm. This enables React Native to interact easily with native platform APIs since React Native wraps existing native code.

Due to these factors, React Native offers many more advantages compared to those earlier hybrid frameworks. We now review them.

#android app #frontend #ios app #mobile app development #benefits of react native #is react native good for mobile app development #native vs #pros and cons of react native #react mobile development #react native development #react native experience #react native framework #react native ios vs android #react native pros and cons #react native vs android #react native vs native #react native vs native performance #react vs native #why react native #why use react native

What are hooks in React JS? - INFO AT ONE

In this article, you will learn what are hooks in React JS? and when to use react hooks? React JS is developed by Facebook in the year 2013. There are many students and the new developers who have confusion between react and hooks in react. Well, it is not different, react is a programming language and hooks is a function which is used in react programming language.
Read More:-

#react #hooks in react #react hooks example #react js projects for beginners #what are hooks in react js? #when to use react hooks

Mark Mara

Mark Mara


Class-less Components in React

While coding this week, I had to convert one of my class components in React to a functional component.

Why would I need to do that? After all, the parent component sees the two types of components as identical. Sure, functional components can be shorter, require less boilerplate, and maybe even perform better. But that’s not why I needed to do it. I was using an npm package that had React hooks and hooks are for functional components only. React Hooks, added in React 16.8, allow functional components to manage state and replace lifecycle methods. To use the hook I needed I had to convert my class components to a functional.

Here are the steps I followed to change my class component to a functional component:

#react-hook-useeffect #useeffect #react-hook #react-hook-usestate #react

Vegard  Sandnes

Vegard Sandnes


Beginner’s Guide to using useState and useEffect React Hooks

You are a developer with previous experience using React, and you are comfortable using React class components. You’re so comfortable with class components to the point that switching to functional components sounds daunting. How are you going to set state? How can you access the react component lifecycle?

If this sounds like you, then this guide will help you begin transitioning your class components into functional ones. React hooks provide an ability to use state and lifecycle functions within functional components.

We will discuss two built in hooks: useState and useEffect.


A key difference between class and functional components is the fact that class components have a state while functional components are stateless. The useState hook allows us to add local state to a functional component. This hook holds onto a state between re-renders.

Let’s start by comparing the different components.

Image for post

Class component showing how to use this.setState

#useeffect #react-hook #usestate #react-components #react

React Component Lifecycle Methods-How They Translate Into React Hooks

I’m on a bit of a React journey at the moment, so I’ve decided to write some blog posts about its key concepts. First on my list is the component lifecycle, which I’ve recently had to get my teeth stuck into!
This article provides an explanation of some of the most useful Lifecycle methods, before showing how to translate these methods into React Hooks.
Image for post

What is the React component Lifecycle?

Just like humans, React components go through their own lifecycles. These lifecycles are composed of several different phases that can be manipulated to run code at different times in the component’s existence. Each phase comes with its own lifecycle methods, which are used to run code at specific times in the program.

#javascript #react #react-hook #useeffect