Type Checking With PropTypes In React

Do PropTypes confuse you? You’re not alone. The notion of PropTypes confused me as well when I first started learning React. But, have no fear, because I’m going to teach you all about PropTypes. They can make your life significantly easier when developing your React apps! I highly suggest that you have some React experience as this is a slightly advanced topic.

Static vs Dynamic Typing

Let’s get right into it. Static typing is where the type is boundto the variable. Dynamic typing is where the type is bound to the value_. _ For example, in a dynamically typed language such as Java:

String address = '123 Coding Street'

So address will now forever be a string. It may point to different strings or even a null value, but it will NEVER be a boolean, Integer, or an Array. Get it? Now let’s look at another example, this time in JavaScript:

var name = 'John Calderaio'
name = true
name = 1234

Do you see how I re-defined the type twice? That’s because JavaScript is dynamically typed. Are you following me? I’m sure you can see the difference.

Understanding Props

To understand PropTypes you must first understand what _props ARE. _Props are a way to pass information between components. It almost always uses uni-directional data flow (Parent to Child components). However, with callback functions, it is possible to pass props back up from a child to a parent component – but that goes beyond the scope of this article. Without PropTypes, you can’t check what type of value a passed prop is inside a component. This is because JavaScript is dynamically-typed. This can lead to errors and unexpected behavior in your code, especially when dealing with a larger code-base.

So, what are PropTypes then?

PropTypes ensure that components are using the data type that the programmer (or you) intended. It can be difficult keeping track of a value’s type in JavaScript. There are many solutions to this, such as flow and TypeScript. But the easiest way to get up and running is by using PropTypes. We can think about them like puppies being bought and imported into a pet store. The pet store doesn’t want snakes, rabbits, frogs, or geckos – they want puppies. PropTypes would ensure that a puppy is being brought into the pet store, and not some other kind of animal. Don’t you wish you had PropTypes in real life to use in circumstances other than code? I know I do!

Let’s Take a Look at Some Code Samples

A code sample speaks a thousand words, so let’s dive right in:

PropTypes has been recently moved into its own npm package. Install by navigating your terminal to the root directory of your project and type: ‘npm install – -save prop-types’. Once it is finished installing, move on.

import React, { Component } from 'react'
import PropTypes from 'prop-types'
export default class State extends Component {
   static propTypes = {
      optionalStateName: PropTypes.string,
      requiredOnChange: PropTypes.func.isRequired,
      optionalCity: PropTypes.instanceOf(City)

As you can probably guess, optionalStateName takes a string and is NOT required for you to pass its corresponding prop. requiredOnChange takes a function and IS required (as denoted by the ‘.isRequired’ suffix. Finally, optionalCity takes a class instance of a class named “City”.

The basic data types that PropTypes use includes: PropTypes.number, PropTypes.string, PropTypes.bool, PropTypes.array, PropTypes.func, PropTypes.object, and PropTypes.symbol. I want you to study up on the countless other PropType “data types“. They can all be found at Facebook’s official PropType React page, here.

Alternate PropType Example

Are you following me so far? If you’re reading this article I can deduce that you’re probably an intelligent individual, so I’m going to assume you “get it”. Now that I’ve shown you an example, let’s take a look at another way in which PropTypes can be declared:

import React, { Component } from 'react'
import PropTypes from 'prop-types'
export default class Person extends Component {
   render() {
      const pizzaPreference = (this.props.likesPizza) ? "does" : "does not"
      return (
         <h1>{this.props.name} is {this.props.age} years old and {pizzaPreference} like pizza!<h1>
Person.propTypes = {
   name: PropTypes.string.isRequired,
   age: PropTypes.number.isRequired,
   likesPizza: PropTypes.bool.isRequired

See the difference between this example and the example from the previous section? The first example declares the PropTypes as a static object inside the class. The second example adds the propType object to the class outside of the class. The two methods have the same effect and it comes down to personal preference as to which you choose.

Error Handling with DefaultProps

In cases where a PropType IS optional (NOT using “.isRequired”), you can use _defaultProps. _ DefaultProps can be used to ensure a prop has a value, in case nothing gets passed. Here is an example:

export default class Car extends Component {
   static defaultProps = {
      company: "Ford"
   static propTypes {
      company: PropTypes.string
   render() {
      <h1>My car is made by {this.props.company}</h1>

Do you see what’s happening? Even if NO company prop is passed to the _Car _class, it has a defaultProperty (“Ford”) to fall back on. This prevents errors when no props are passed. I suggest you use defaultProps for every optional PropType.


If you REALLY want to become a React master, you are going to have to get familiar with PropTypes. They can bring organization and type checking to a language (JavaScript) severely lacking in that department.


Let’s recap what you’ve learned in this article:

  • Static vs Dynamic Typing (Static is where the type is boundto the variable. Dynamic is where the type is bound to the value).
  • Props are a way to pass information between components.
  • PropTypes ensure that components are using the data type that the programmer (or you) intended.
  • They have been recently moved into their own npm package, so make sure to import them at the top of your JavaScript file.
  • PropTypes can be declared as a static object inside of a React class or added onto a previously declared class. ex “Class.propType = { }”
  • A PropType can be made required by adding the “.isRequired” suffix
  • The basic PropType data types include number, string, bool, array, func, object, and symbol. There are also many others that I implore you to research.
  • DefaultProps can be used to ensure a prop has a value, in case no data for that prop gets passed along.

The Original Article can be found on programmingwithmosh.com

#react #javascript #programming #web-development #developer

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Type Checking With PropTypes 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.

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Mathew Rini


How to Select and Hire the Best React JS and React Native Developers?

Since March 2020 reached 556 million monthly downloads have increased, It shows that React JS has been steadily growing. React.js also provides a desirable amount of pliancy and efficiency for developing innovative solutions with interactive user interfaces. It’s no surprise that an increasing number of businesses are adopting this technology. How do you select and recruit React.js developers who will propel your project forward? How much does a React developer make? We’ll bring you here all the details you need.

What is React.js?

Facebook built and maintains React.js, an open-source JavaScript library for designing development tools. React.js is used to create single-page applications (SPAs) that can be used in conjunction with React Native to develop native cross-platform apps.

React vs React Native

  • React Native is a platform that uses a collection of mobile-specific components provided by the React kit, while React.js is a JavaScript-based library.
  • React.js and React Native have similar syntax and workflows, but their implementation is quite different.
  • React Native is designed to create native mobile apps that are distinct from those created in Objective-C or Java. React, on the other hand, can be used to develop web apps, hybrid and mobile & desktop applications.
  • React Native, in essence, takes the same conceptual UI cornerstones as standard iOS and Android apps and assembles them using React.js syntax to create a rich mobile experience.

What is the Average React Developer Salary?

In the United States, the average React developer salary is $94,205 a year, or $30-$48 per hour, This is one of the highest among JavaScript developers. The starting salary for junior React.js developers is $60,510 per year, rising to $112,480 for senior roles.

* React.js Developer Salary by Country

  • United States- $120,000
  • Canada - $110,000
  • United Kingdom - $71,820
  • The Netherlands $49,095
  • Spain - $35,423.00
  • France - $44,284
  • Ukraine - $28,990
  • India - $9,843
  • Sweden - $55,173
  • Singapore - $43,801

In context of software developer wage rates, the United States continues to lead. In high-tech cities like San Francisco and New York, average React developer salaries will hit $98K and $114per year, overall.

However, the need for React.js and React Native developer is outpacing local labour markets. As a result, many businesses have difficulty locating and recruiting them locally.

It’s no surprise that for US and European companies looking for professional and budget engineers, offshore regions like India are becoming especially interesting. This area has a large number of app development companies, a good rate with quality, and a good pool of React.js front-end developers.

As per Linkedin, the country’s IT industry employs over a million React specialists. Furthermore, for the same or less money than hiring a React.js programmer locally, you may recruit someone with much expertise and a broader technical stack.

How to Hire React.js Developers?

  • Conduct thorough candidate research, including portfolios and areas of expertise.
  • Before you sit down with your interviewing panel, do some homework.
  • Examine the final outcome and hire the ideal candidate.

Why is React.js Popular?

React is a very strong framework. React.js makes use of a powerful synchronization method known as Virtual DOM, which compares the current page architecture to the expected page architecture and updates the appropriate components as long as the user input.

React is scalable. it utilises a single language, For server-client side, and mobile platform.

React is steady.React.js is completely adaptable, which means it seldom, if ever, updates the user interface. This enables legacy projects to be updated to the most new edition of React.js without having to change the codebase or make a few small changes.

React is adaptable. It can be conveniently paired with various state administrators (e.g., Redux, Flux, Alt or Reflux) and can be used to implement a number of architectural patterns.

Is there a market for React.js programmers?
The need for React.js developers is rising at an unparalleled rate. React.js is currently used by over one million websites around the world. React is used by Fortune 400+ businesses and popular companies such as Facebook, Twitter, Glassdoor and Cloudflare.

Final thoughts:

As you’ve seen, locating and Hire React js Developer and Hire React Native developer is a difficult challenge. You will have less challenges selecting the correct fit for your projects if you identify growing offshore locations (e.g. India) and take into consideration the details above.

If you want to make this process easier, You can visit our website for more, or else to write a email, we’ll help you to finding top rated React.js and React Native developers easier and with strives to create this operation

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Franz  Becker

Franz Becker


React Starter Kit: Build Web Apps with React, Relay and GraphQL.

React Starter Kit — "isomorphic" web app boilerplate   

React Starter Kit is an opinionated boilerplate for web development built on top of Node.js, Express, GraphQL and React, containing modern web development tools such as Webpack, Babel and Browsersync. Helping you to stay productive following the best practices. A solid starting point for both professionals and newcomers to the industry.

See getting started guide, demo, docs, roadmap  |  Join #react-starter-kit chat room on Gitter  |  Visit our sponsors:



Getting Started


The master branch of React Starter Kit doesn't include a Flux implementation or any other advanced integrations. Nevertheless, we have some integrations available to you in feature branches that you can use either as a reference or merge into your project:

You can see status of most reasonable merge combination as PRs labeled as TRACKING

If you think that any of these features should be on master, or vice versa, some features should removed from the master branch, please let us know. We love your feedback!



React Starter Kit

React Static Boilerplate

ASP.NET Core Starter Kit

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LanguageJavaScript (ES2015+, JSX)JavaScript (ES2015+, JSX)JavaScript (ES2015+, JSX)
LibrariesReact, History, Universal RouterReact, History, ReduxReact, History, Redux
RoutesImperative (functional)DeclarativeDeclarative, cross-stack
LanguageJavaScript (ES2015+, JSX)n/aC#, F#
LibrariesNode.js, Express, Sequelize,
n/aASP.NET Core, EF Core,
ASP.NET Identity
Data APIGraphQLn/aWeb API


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Anyone and everyone is welcome to contribute to this project. The best way to start is by checking our open issues, submit a new issue or feature request, participate in discussions, upvote or downvote the issues you like or dislike, send pull requests.

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  • GraphQL Starter Kit — Boilerplate for building data APIs with Node.js, JavaScript (via Babel) and GraphQL
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Copyright © 2014-present Kriasoft, LLC. This source code is licensed under the MIT license found in the LICENSE.txt file. The documentation to the project is licensed under the CC BY-SA 4.0 license.

Author: kriasoft
Source Code: https://github.com/kriasoft/react-starter-kit
License: MIT License

#graphql #react 

Juned Ghanchi


React Native App Developers India, React Native App Development Company

Expand your user base by using react-native apps developed by our expert team for various platforms like Android, Android TV, iOS, macOS, tvOS, the Web, Windows, and UWP.

We help businesses to scale up the process and achieve greater performance by providing the best react native app development services. Our skilled and experienced team’s apps have delivered all the expected results for our clients across the world.

To achieve growth for your business, hire react native app developers in India. You can count on us for all the technical services and support.

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Aubrey  Price

Aubrey Price


React PropTypes and DefaultProps - Type Checking in React JS

React PropTypes and DefaultProps Explained
Learn type checking for Props in React JS by using PropTypes. In programming, type checking is important. We can use TypeScript for writing secure data types in React, but it doesn’t work for Props.

In this video, you’re going to learn how to use type checking in React JS with an external npm package: PropTypes. I will also explain what default props mean and how to use it.

#react #react js #react-native