Introduction to
Inheritance in React JS
React JS has made web development an easier task. With its advanced features, it has become a go-to platform for web developers.
One of the fundamental concepts of React JS is inheritance. It is the ability of a class to inherit properties from another class.
Inheritance is a powerful tool that helps in creating reusable code and saves time in the development process.
Inheritance in React JS
Inheritance is a mechanism where one class acquires the properties of another class. It is a vital concept in React JS, which helps in creating components that share the same functionalities.
This means that a new class can be defined based on an existing class, and the new class will inherit all the properties of the existing class. Therefore, inheritance in React JS is a way of creating a hierarchy of classes that share the same functionalities.
Use of extends keyword in React JS
The extends keyword is a crucial concept in React JS that helps in creating a child class inheriting properties from the parent class. The child class can add its own properties or methods, which the parent class does not already have.
The syntax for using the extends keyword in React JS is as follows:
class ChildClass extends React.Component {
// code for the child class
}
Here, the ChildClass is the child class that inherits properties from React.Component, which is the parent class. You should note that React.Component is an essential class in React JS and should not be regarded as an ordinary class.
Example of
Inheritance in React JS
Let us consider an example to demonstrate the usefulness of inheritance in React JS. In this example, we will show how a child class inherits the properties of the parent class.
Code Example
import React from ‘react’;
class ParentClass extends React.Component {
render() {
return (
This is the Parent Class
);
}
}
class ChildClass extends ParentClass {
render() {
return (
This is the Child Class
);
}
}
Here, we have created two classes, ParentClass and ChildClass. The ParentClass is the parent, and the ChildClass is the child.
The ChildClass inherits the properties of the ParentClass. The syntax for the class to class reference is as follows:
class ChildClass extends ParentClass
In the example, the ChildClass overrides the render method of the ParentClass. The render method for the ChildClass displays “This is the Child Class” instead of “This is the Parent Class,” which is displayed by the render method of the ParentClass.
Syntax for class-to-class reference
The syntax for class-to-class reference is straightforward. You need to use the extends keyword and refer to the parent class.
For instance, in the above example, ChildClass extends ParentClass, where ParentClass is the base class.
Importing and accessing elements within a class
You might also need to import and access elements within a class. This is where inheritance is vital.
You can access the elements of the parent class in the child class using the super keyword, which calls the constructor function of the parent class. Here is an example of how to import and access elements within a class:
import React from ‘react’;
class ParentClass extends React.Component {
constructor(props) {
super(props);
this.state = {
name: ‘Parent Class’
}
}
render() {
return (
{this.state.name}
);
}
}
class ChildClass extends ParentClass {
constructor(props) {
super(props);
}
render() {
return (
{this.state.name}
);
}
}
Here, we have imported the state object from the ParentClass. The super keyword is used in the constructor function of the ChildClass to call the constructor function of the ParentClass.
This allows us to access the properties of the ParentClass in the ChildClass.
Conclusion
Inheritance in React JS is a powerful concept that helps in creating reusable code and saves time in the development process. The extends keyword is a vital tool for creating a child class that inherits properties from the parent class.
The syntax for class-to-class reference is straightforward, and importing and accessing elements within a class is achievable using the super keyword. As you delve deeper into React JS, you will appreciate the usefulness of inheritance in developing web applications.
3) Extending Components from Another Class in React JS
Extending components from another class in React JS is another common use case that helps in creating reusable code. In this process, a component inherits all the properties, methods, and state of the parent component.
This makes it easier to implement and use common functionality throughout an application.
Example of Extending Components from Another Class
Here is an example of how to extend components from another class in React JS:
import React from ‘react’;
class ParentComponent extends React.Component {
constructor(props) {
super(props);
this.state = {
name: “Parent Component”
};
}
sayHello() {
console.log(“Hello from Parent Component”);
}
}
class ChildComponent extends ParentComponent {
render() {
return (
Hello World
{this.state.name}
);
}
}
Here, we have two components, the ParentComponent, and the ChildComponent. The ChildComponent extends the ParentComponent, and therefore it inherits all the properties and state of the ParentComponent.
Additionally, we have defined a function in the ParentComponent called sayHello(). The ChildComponent can access this method as well.
Creating a Class with Function in React JS
React JS components can be created as classes with functions. Here’s an example:
import React, {Component} from ‘react’;
class HelloWorld extends Component{
constructor(props){
super(props)
}
sayHello(){
console.log(‘Hello World’)
}
render(){
return(
Hello World
)
}
}
Here, we have created a component called HelloWorld.
It is defined as a class that extends the Component class of React. The constructor is defined, which takes in props as its argument.
We have also defined a function named sayHello(). Inside the render method, we have created a button element that calls the function when clicked.
Extending a Class in React JS
Extending a class in React JS is the process of inheriting all the properties of a class, mostly useful when developing customized components. To extend a class, we use the extends keyword followed by the parent class name.
Here is an example:
import React, { Component } from “react”;
class Parent extends Component {
constructor(props) {
super(props);
this.state = { name: “Parent” };
}
render() {
return
{this.state.name}
;
}
}
class Child extends Parent {
constructor(props) {
super(props);
this.state = { name: “Child” };
}
}
Here, we have two classes, the Parent class and the Child class that extends the Parent class using the extends keyword.
4) Running a React JS Project with an Example
When it comes to running a React JS project, there are basic steps you should follow to get started. These steps are:
Installation of react-select package for React JS project
React select is a widely used package in React JS, and we’ll show you how to install it for a new project. You will need to have Node.js and NPM installed on your system before proceeding.
Once you have those, follow these steps:
– Open your terminal or command prompt. – Change your directory into the project folder.
– Run the following command to install the react-select package:
npm install –save react-select
Running a React JS project with the latest Node JS version
To run a React JS project, you will need to have Node.js installed on your system. Here are the steps to follow:
– Open your terminal or command prompt.
– Change your directory into the project folder. – Run the following command to install the dependencies for the project (assuming that you have your package.json file ready):
npm install
– Finally, run the below command to start the project:
npm start
These steps help to run a new or existing React JS project on your system.
Conclusion
In this article, we have discussed various topics related to React JS to help you better understand how to extend components from another class, creating classes with functions, and running a React JS project on your system. All these concepts are essential to know when developing React JS applications and can be used to create reusable and extendable code.
In this article, we discussed the fundamental concepts of inheritance in React JS that are crucial in creating reusable code and saving development time. We covered how to extend components from another class, create classes with functions, and run a React JS project with an example.
The use of inheritance not only helps maintain a clean code structure, but it also aids in creating a hierarchy of classes that share the same functionality. As you delve deeper into React JS, you will appreciate the usefulness of inheritance and how it can be used to develop web applications efficiently.
Remember to consider using these concepts in your next React JS project.