How to load data using Lifecycle Methods in React.js?

What is a Lifecycle Method in React.js? » In the previous section you learned that data loading must be done inside the componentDidMount() method as opposed to the constructor() function. It is not mandatory to do it like this, but it is a good community practice among good React developers. Right now, you’re getting the … Read moreHow to load data using Lifecycle Methods in React.js?

What is a Lifecycle Method in React.js?

What is a Lifecycle Method in React.js? » These are the functions which you can optionally define right inside the class based components. If you choose to define these methods, they’ll be called automatically by React at certain point of the app’s lifecycle. That’s why these methods are called Lifecycle Methods. You’ve already seen the … Read moreWhat is a Lifecycle Method in React.js?

How to handle errors in a component and state in React.js?

How to use states in React.js » Let’s try to simulate some errors in your App component to learn how to deal with them. Add a new property called hasError to the state in App component and initialize it with default value of true as follows:       this.state = {hrs: ”, hasError: true}; Next, make … Read moreHow to handle errors in a component and state in React.js?

How to update state properties in a component in React.js using setState()?

How to use states in React.js » Now that you’ve declared state object inside the constructor method, you can now access this object from anywhere in the component. Let’s try to access it from the return() method. To do that, you can access the hours property from the state object as follows: return <div>Current hour … Read moreHow to update state properties in a component in React.js using setState()?

How to initialize default state object in constructor in a component in React.js?

How to use states in React.js » Once you have the constructor function defined, you can define state variable values there (assign values to initialize object). Here, the only relevant property you may want to define is the hrs variable. All the variable are defined inside this.state object. For instance: this.state = {hrs: }; Whenever … Read moreHow to initialize default state object in constructor in a component in React.js?

Why do we need to call super(props) in constructor function in React.js?

How to use states in React.js » class App extends React.Component { constructor(props) {     super(props); } … } In the above code, you have extended React.Component to App component. Do note that that React.Component also has its own constructor() method and a set of initialization. However, when you create a constructor method inside App … Read moreWhy do we need to call super(props) in constructor function in React.js?

How to initialize states using constructors in React.js?

How to use states in React.js » The first thing you need to make sure is to initialize states when you first create your component. You also need to make sure you assign the actual data and update the app state once you have the updated data available. You can initialize the state variables with … Read moreHow to initialize states using constructors in React.js?

How to convert a function based component into a class based component in React.js?

How to use class based components in React.js? » Now, you need to put all these knowledge together to convert the function based component App into a class based component. Modify the code in index.js so that it looks like: import React from ‘react’; import ReactDOM from ‘react-dom’; class App extends React.Component {     render(){ … Read moreHow to convert a function based component into a class based component in React.js?