What Is ReactJS Props

In ReactJS, the value of a tag's attributes is kept in an object type called ReactJS props. Properties are implied by the word "props," and HTML attributes' workings are pretty similar. These ReactJS prop components are simply read-only components. In this article, we will talk more about the props in ReactJS, props in functional components, ReactJS default props, and the state with props.

What are ReactJS Props?

Although "props" is short for "properties," ReactJS refers to it as a concept. The props are essentially objects. It keeps track of a Tag's attribute values. Similar to JavaScript function arguments and HTML properties are React Props.

Let us see a simple ReactJS code for using props:
class Hello extends React.Component 

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Code Output:

Hello Hey

Features of ReactJS props are:

  • React components receive props as arguments.
  • Components receive props through HTML attributes.
  • Properties can have default values created using props.spmeProp
  • Properties can have values set someProp from the tag's someProp attribute.
  • There is no method to change the props values from within the Component (class).
  • The React Props API is read-only. If you attempt to alter their value, an error will be returned.

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Passing Data using Props in ReactJS

Props are another method for transferring data between components as parameters. 

Let us see an example to understand this better

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Code output:

Who are wild animals?
I am a Tiger!

Props in ReactJS Functional Component

A component is a standalone, reusable code block that separates the user interface into manageable chunks. For instance, suppose we were using React to create Twitter's user interface:

Props in ReactJS Functional

Instead of creating the entire UI in a single document, the user can and ought to separate all the components (highlighted in red) into more manageable, independent parts. Or to put it another way, these are parts.
Both functional and class components are available in React.

Functional Component
Functional components are the first and best form of the component in React. A JS ES6 function producing a React element is basically what makes up a functional component in JSX. The following function is a legitimate functional component, as according to React's documentation.

Let us see below an example of a functional component:

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Consequently, a React functional component is:

This function accepts a single "props" object parameter with data and produces a React element, making it a legitimate React component.

  • It should give output as a React element
  • It is a JavaScript ES6 function
  • It always begins with an uppercase and, if required, accepts props as a variable parameter.

Props in React js Class component

The class component is the second category of the component. ES6 classes that yield JSX make up class components. You can see the Greetings function below, but this time it's being used as a ReactJS class component.

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We only needed functional components to generate the user interface (UI), whereas class components were used for data management and a few other activities.

A class component has the following features:

  • It is an ES6 class
  • It "extends" a React component, which will become a component.
  • It must have a render() method that returns JSX and takes Props in the function Object(), if necessary.

Default Props in ReactJS

A user can specify default parameters for the argument in props by using the defaultProps React component property. The prop property will be altered if it is passed. For establishing default props for a class, the defaultProps property can be defined as a setting on the element class itself.

Let us see an example below to understand the working of default props.

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Let us see another example of default props:
App.js

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Main.js

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Code output:

header from props 2

State and Props

We are utilizing props to convey the state of the component hierarchy after setting it in our parent component. We set the headerProp as well as contentProp used during child components inside the render function.

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Main.JS

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The outcome will be identical to that of the first two cases; the only distinction is that our data now originates from the state rather than the federal government. All descendant components get updated if we simply update the state when we wish to update it.

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header from props

ReactJS prop Types

PropTypes in React is used for the verification of the data type of the provided value in props. These propTypes make sure that we don't wind up with a console error that may be difficult to troubleshoot.
The simplest approach to determine whether a propTypes is a primitive type in JS such as a boolean, object, string, etc. is to look at its type.

basic prop types

collective prop types

object types 1

How to Use Props in React

Since React 15.5, propTypes have been included in the ReactJS library. But now our project needs to include a prop-types library.
Use the command below for the installation of the prop-types library.

npm install prop-types save

PropTypes are used to verify any data that the user receives in props. But in order to utilize propTypes, he must import as usual in our application:

import PropTypes from 'prop-types';

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Conclusion :
In this tutorial, we have discussed props in ReactJS. the value of a tag's attributes is kept in an object type called ReactJS props. Although "props" is short for "properties," ReactJS refers to it as a concept. The props are essentially objects. It keeps track of a Tag's attribute values. Similar to JavaScript function arguments and HTML properties are React Props.
We have also talked about props in functional components, ReactJS default props, and the state with props.

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Amani
Amani
Research Analyst
As a content writer at HKR trainings, I deliver content on various technologies. I hold my graduation degree in Information technology. I am passionate about helping people understand technology-related content through my easily digestible content. My writings include Data Science, Machine Learning, Artificial Intelligence, Python, Salesforce, Servicenow and etc.

ReactJS Props FAQs

When React Hooks were originally introduced, many programmers still used render props. Render properties have grown to provide various new features, therefore they haven't fully disappeared and never will.

Step 1: The user needs to pass the arguments using props.

Step 2: Declare the props variable(s) as const name = props

Step 3: Use the variables in the JSX template

Step 4: Pass data to the app component's properties.

Although "props" is short for "properties," ReactJS refers to it as a concept. The props are essentially objects. It keeps track of a Tag's attribute values. Similar to JavaScript function arguments and HTML properties are React Props.

Data that may be accessible by a React component's children is stored in props. They are a component of the idea of reuse. Props replace class attributes and give you the ability to design uniform interfaces throughout the component hierarchy.

Bool, number, object, and string are the four most common types of props in ReactJS