How To Write Better Code in React

How To Write Better Code in React

9 Useful Tips for writing better code in React: Learn about Linting, propTypes, PureComponent and more.

React makes it painless to create interactive UIs. Design simple views for each state in your application, and React will efficiently update and render just the right components when your data changes.

In this post, I will show you a few tips that will help you become a better React Developer. I will cover a range of things from tooling to actual code style, which can help you improve your skill with React. 💪

Let’s Talk about Linting

One thing that’s really important for writing better code is good linting. Because if we have a good set of linting rules set up, your code editor will be able to catch anything that could potentially cause a problem in your code.

But more than just catching problems, your ES Lintsetup will constantly make you aware of React best practices.

import react from 'react';
/* Other imports */

/* Code */

export default class App extends React.Component {
  render() {
    const {userIsLoaded, user} = this.props;
    if (!userIsLoaded) return ;
    
    return (
      /* Code */
    )
  }
}

lint.js

Take the code snippet above. Say you want to reference a new property called this.props.hello in your render() function. Your linter will immediately go red and say:

'hello' is missing in props validation (react/prop-types)

Linting will help you be aware of the best practices in React and shape your understanding of the code. Soon, you will start to avoid making mistakes when you write your code.

You can either head over to ESLint and set up a linting utility for JavaScript, or you can use Airbnb’s JavaScript Style Guide. You can also install the React ESLint Package.

Leverage component modularity, reuse and composition

Use tools like Bitto build modular apps faster with reusable components.

Using Bit you can quickly share and organize all your React components, which can then be used and developed in any other project.

Bit helps you isolate and share components from any project. Then, they become reusable “Lego pieces” you can find, play with and use anywhere.

It’s a great platform for turning component reusability into a way to build more applications in less time. Give it a go.

propTypes and defaultProps

In the earlier section, I talked about how my linter acted up when I tried to pass an unvalidated prop.

static propTypes = {
  userIsLoaded: PropTypes.boolean.isRequired,
  user: PropTypes.shape({
    _id: PropTypes.string,
  )}.isRequired,
}

proptypes.js

Here, if we say that the userIsLoaded is not required, then we would need to add this to our code:

static defaultProps = {
 userIsLoaded: false,
}

So anytime we have a PropType that’s used in our component, we need to set a propType for it. As in, we need to tell React that userIsLoaded is always going to be a boolean value.

And again if we say that userIsLoaded is not required then we’re going to need to have a default prop. If it is required, then we don’t have to define a default prop for it. However, the rule also states that you shouldn’t have an ambiguous propTypes like object or array.

This is why we are using shape to validate user, which has another an id inside it, which has a propType of string, and the entire user object is required.

Making sure you have your propTypes and defaultProps set up on every single component that uses props will go a long way.

The moment those props don’t get the data that they are expecting, your error log will let you know that you are either passing in something incorrectly or something that is expecting it is not there, making error finding just way easier especially if you are writing a lot of reusable components. It also makes them a little bit more self-documenting.

Note:

Unlike earlier versions of React, proptypes are no longer included inside React and you will have to add them separately to your project as a dependency.

Know when to make new components

export default class Profile extends PureComponent {
  static propTypes = {
    userIsLoaded: PropTypes.bool,
    user: PropTypes.shape({
      _id: PropTypes.string,
    }).isRequired,
  }

  static defaultProps = {
    userIsLoaded: false,
  }

  render() {
    const { userIsLoaded, user } = this.props;
    if (!userIsLoaded) return ;
    return (
      
        
          
            
            
          
          
            
            
          
        
        
          {isRole('affiliate', user={user._id} &&
            
          }
        
      
    )
  }
}
      

profile.js

Here I have a component called Profile. I have other components like MyOrder and MyDownloads inside this component. Now I could have written all these components inline here since I am just pulling the data from the same place (user), Turning all these smaller components into a one giant component.

While there aren’t any hard and fast rules on when to move your code into a component, ask yourself:

  • Is your code’s functionality becoming unwieldy?
  • Does it represent its own thing?
  • Are you going to reuse your code?

If any of these question’s answer is yes, then you need to move your code into a component.

Keep in mind that the last thing anyone wants to see in your code is a giant 200–300 line component full of crazy bells and whistles.

Component vs PureComponent vs Stateless Functional Component

It is very important for a React developer to know when to use a Component, PureComponent, and a Stateless Functional Component in your code.

You might have noticed in the above code snippet that instead of declaring Profile as a Component, I have instead called it as a PureComponent.

First, let’s check out a stateless functional component.

Stateless Functional Component

const Billboard = () => (
  
    React
    
      
        ![](#)
      
      
        ### React

        
Lorem Ipsum

      
    
  
);

stateless.js

Stateless functional components are one of the most common types of components in your arsenal. They provide us with a nice and concise way to create components that are not using any kind of state, refs, or lifecycle methods.

The idea with a stateless functional component is that it is state-less and just a function. So what’s great about this is that you are defining your component as a constant function that returns some data.

In simple words, stateless functional components are just functions that return JSX.

Update: React’s latest version has brought us React hooks, which will let us state, effects and refs in functional components without needing to convert them into class components.

PureComponents

Usually, when a component gets a new prop into it, React will re-render that component. But sometimes, a component gets new props that haven’t really changed, but React will still trigger a re-render.

Using PureComponent will help you prevent this wasted re-render. For instance, if a prop is a string or boolean and it changes, a PureComponent is going to recognize that, but if a property within an object is changing, a PureComponent is not going to trigger a re-render.

So how will you know when React is triggering an unnecessary re-render? You can check out this amazing React package called Why Did You Update. This package will notify you in the console when a potentially unnecessary re-render occurs.

Once you have recognized an unnecessary re-render, you can use a PureComponent rather than a Component to prevent things from having an unnecessary re-render.

Use React Dev Tools

If you are serious about becoming a pro React Developer, then using React Dev Tools should be commonplace practice in your development process.

If you have used React, there is a good chance that your console has yelled at you to use React Dev Tools.

React Dev Tools are available for all major browsers such as Chrome and Firefox.

React Dev Tools give you access to the entire structure of your React app and allow you to see all the props and state that are being used in the app.

React Dev Tools is an excellent way to explore our React components and helps diagnose any issues in your app.

Use Inline Conditional Statements

This opinion might ruffle a few feathers but I have found that using Inline-Conditional Statements considerably cleans up my React code.

Take a look at this code snippet:


  {isRole('affiliate', user._id) &&
    
  }

conditional.js

Here I have a basic function called that checks if a person is an “affiliate”, followed by a component called ``.

What’s great about this is that:

  • I didn’t have to write a separate function.
  • I didn’t have to write another “if” statement in my render function.
  • I didn’t have to create a “link” to somewhere else in the component.

Writing inline-conditional statements is quite simple. You begin by writing you conditional statement. You could say true and it will always show the `` component.

Next we link this conditional statement with `` using &&. This way, the component will only be rendered when the conditional statement returns true.

Use Snippet Libraries whenever possible

Open up a code editor (I use VS Code), and create a .js file.

Inside this file when you type rc, you will see something like this:

Hitting enter, you will instantly get this:

What’s great about these code snippets is that not only do they help you potentially save bugs but they also help you identify the latest and greatest syntax.

There are many different snippet libraries that can be installed in your code editor. The one I use for VS Code is called ES7 React/Redux/React-Native/JS Snippets.

React Internals — Learn how React works

React Internals is a five-part series that helped me understand the very basics of React, and eventually helped me become a better React Developer!

If you are having issues with something that you might not have understood fully, or if you understand how React works, then React Internals will help you understand the When and How to do things right in React.

This is especially helpful to those who have an idea but don’t quite know where to execute their code.

Understanding the basics of how React works will help you become a better React developer.

Quick Recap

  1. Get some good linting. Use ES Lint, Airbnb’s JavaScript Style Guide, and ESLint React Plugin.
  2. Use propTypes and defaultProps.
  3. Know when to make new components.
  4. Know when to write a Component, PureComponent, and a Stateless Functional Component.
  5. Use React Dev Tools.
  6. Use inline conditional statements in your code.
  7. Use Snippet Libraries to save a ton of time that is usually wasted on boilerplate code.
  8. Learn how React works with React Internals.
  9. Use tools like Bit / StoryBook to improve your component development workflow

Learn more

Master ReactJS: Learn React JS from Scratch

Learn ReactJS: Code Like A Facebook Developer

ReactJS Course: Learn JavaScript Library Used by Facebook&IG

React: Learn ReactJS Fundamentals for Front-End Developers

React From The Ground Up

What is JavaScript – All You Need To Know About JavaScript

What is JavaScript – All You Need To Know About JavaScript

In this article on what is JavaScript, we will learn the basic concepts of JavaScript.

After decades of improvement, JavaScript has become one of the most popular programming languages of all time. It all started in the year 1995 when Brendan Eich created JavaScript in a span of 10 days. Since then, it has seen multiple versions, updates and has grown to the next level.

Here’s a list of topics that I’ll be covering in this blog:

  1. What is JavaScript
  2. What can JavaScript do?
  3. JavaScript Frameworks
  4. The Big Picture: HTML, CSS & JavaScript
  5. Benefits of JavaScript
  6. Fundamentals of JavaScript
    VariablesConstantsData TypesObjectsArraysFunctionsConditional statementsLoopsSwitch case
What is JavaScript?

JavaScript is a high level, interpreted, programming language used to make web pages more interactive.

Have you ever thought that your website is missing something? Maybe it’s not engaging enough or it’s not as creative as you want it to be. JavaScript is that missing piece which can be used to enhance web pages, applications, etc to provide a more user-friendly experience.

What is JavaScript?

JavaScript is the language of the web, it is used to make the web look alive by adding motion to it. To be more precise, it’s a programming language that let’s you implement complex and beautiful things/design on web pages. When you notice a web page doing more than just sit there and gawk at you, you can bet that the web page is using JavaScript.

Feature of JavaScript

Scripting language and not Java: In fact, JavaScript has nothing to do with Java. Then why is it called “Java” Script? When JavaScript was first released it was called Mocha, it was later renamed to LiveScript and then to JavaScript when Netscape (founded JavaScript) and Sun did a license agreement. Object-based scripting language which supports polymorphism, encapsulation and to some extent inheritance as well.**Interpreted language: **It doesn’t have to be compiled like Java and C which require a compiler.JavaScript runs in a browser: You can run it on Google Chrome, Internet Explorer, Safari, etc. JavaScript can execute not only in the browser but also on the server and any device which has a JavaScript Engine.

What is JavaScript – Stackoverflow stats

Currently, we have 100s of programming languages and every day new languages are being created. Among these are few powerful languages that bring about big changes in the market and JavaScript is one of them.

JavaScript has always been on the list of popular programming languages. According to StackOverflow, for the 6th year in a row, JavaScript has remained the most popular and commonly used programming language.

What can JavaScript do?

JavaScript is mainly known for creating beautiful web pages & applications. An example of this is Google Maps. If you want to explore a specific map, all you have to do is click and drag with the mouse. And what sort of language could do that? You guessed it! It’s JavaScript.JavaScript can also be used in smart watches. An example of this is the popular smartwatch maker called Pebble. Pebble has created Pebble.js which is a small JavaScript Framework that allows a developer to create an application for the Pebble line of watches in JavaScript.

What is JavaScript – Applications of JavaScript
Most popular websites like Google, Facebook, Netflix, Amazon, etc make use of JavaScript to build their websites.Among things like mobile applications, digital art, web servers and server applications, JavaScript is also used to make Games. A lot of developers are building small-scale games and apps using JavaScript.## JavaScript Frameworks

One major reason for the popularity of JavaScript is the JavaScript Frameworks. Here’s a brief introduction of the most trending JavaScript frameworks :

  1. AngularJS is Google’s web development framework which provides a set of modern development and design features for rapid application development.

  2. ReactJS is another top JavaScript framework mainly maintained by Facebook and it’s behind the User Interface of Facebook and Instagram, showing off its efficiency in maintaining such high traffic applications.

What is JavaScript – JavaScript Frameworks

  1. MeteorJS is mainly used for providing back-end development. Using JavaScript on the back-end to save time and build expertise is one of the major ideas behind Meteor.

  2. jQuery can be used when you want to extend your website and make it more interactive. Companies like Google, WordPress and IBM rely on jQuery.

The Big Picture: HTML, CSS & JavaScript

Anyone familiar with JavaScript knows that it has something to do with HTML and CSS. But what is the relationship between these three? Let me explain this with an analogy.

What is JavaScript – HTML, CSS and JavaScript

Think of HTML (HyperText Markup Language) as the skeleton of the web. It is used for displaying the web.

On the other hand, CSS is like our clothes. We put on fashionable clothes to look better. Similarly, the web is quite stylish as well. It uses CSS which stands for Cascading Style Sheets for styling purpose.

Then there is JavaScript which puts life into a web page. Just like how kids move around using the skateboard, the web also motions with the help of JavaScript.

Benefits of JavaScript

There has to be a reason why so many developers love working on JavaScript. Well, there are several benefits of using JavaScript for developing web applications, here’s a few benefits:

It’s easy to learn and simple to implement. It is a weak-type programming language unlike the strong-type programming languages like Java and C++, which have strict rules for coding.

It’s all about being fast in today’s world and since JavaScript is mainly a client-side programming language, it is very fast because any code can run immediately instead of having to contact the server and wait for an answer.

Rich set of frameworks like AngularJS, ReactJS are used to build web applications and perform different tasks.

**Builds interactive websites: **We all get attracted to beautifully designed websites and JavaScript is the reason behind such attractive websites and applications.

JavaScript is an interpreted language that does not require a compiler because the web interprets JavaScript. All you need is a browser like Google Chrome or Internet Explorer and you can do all sorts of stuff in the browser.

JavaScript is platform independent and it is supported by all major browsers like Internet Explorer, Google Chrome, Mozilla Firefox, Safari, etc.

JavaScript Fundamentals

In this What is JavaScript blog, we’ll cover the following basic fundamentals of JavaScript
VariablesConstantsData TypesObjectsArraysFunctionsConditional statementsLoopsSwitch case## Variables

Variable is a name given to a memory location which acts as a container for storing data temporarily. They are nothing but reserved memory locations to store values.

What is JavaScript – Variables

To declare a variable in JavaScript use the ‘let’ keyword. For example:

let age;
age=22;

In the above example, I’ve declared a variable ‘age’ by using the ‘let’ keyword and then I’ve stored a value (22) in it. So here a memory location is assigned to the ‘age’ variable and it contains a value i.e. ’22’.

Constants

Constants are fixed values that don’t change during execution time.

To declare a constant in JavaScript use the ‘const’ keyword. For example:

const mybirthday;
mybirthday='3rd August'; 

Data types

You can assign different types of values to a variable such as a number or a string. In JavaScript, there are two categories of data types :

What is JavaScript – Data Types

Objects

An object is a standalone entity with properties and types and it is a lot like an object in real life. For example, consider a girl, whose name is Emily, age is 22 and eye-color is brown. In this example the object is the girl and her name, age and eye-color are her properties.

What is JavaScript – Objects example

Objects are variables too, but they contain many values, so instead of declaring different variables for each property, you can declare an object which stores all these properties.

To declare an object in JavaScript use the ‘let’ keyword and make sure to use curly brackets in such a way that all property-value pairs are defined within the curly brackets. For example:

let girl= {
name: 'Emily',
age: 22,
eyeColour: 'Brown'
};

In the above example, I’ve declared an object called ‘girl’ and it has 3 properties (name, age, eye colour) with values (Emily, 22, Brown).

Arrays

An array is a data structure that contains a list of elements which store multiple values in a single variable.

For example, let’s consider a scenario where you went shopping to buy art supplies. The list of items you bought can be put into an array.

What is JavaScript – Arrays example

To declare an array in JavaScript use the ‘let’ keyword with square brackets and all the array elements must be enclosed within them. For example:

let shopping=[];
shopping=['paintBrush','sprayPaint','waterColours','canvas'];

In the above example I’ve declared an array called ‘shopping’ and I’ve added four elements in it.

Also, array elements are numbered from zero. For example this is how you access the first array element:

shopping[0];		

Functions

A function is a block of organised, reusable code that is used to perform single, related action.

Let’s create a function that calculates the product of two numbers.

To declare a function in JavaScript use the ‘function’ keyword. For example:

function product(a, b) {
return a*b;
}

In the above example, I’ve declared a function called ‘product’ and I’ve passed 2 parameters to this function, ‘a’ and ‘b’ which are variables whose product is returned by this function. Now, in order to call a function and pass a value to these parameters you’ll have to follow the below syntax:

product(8,2);

In the above code snippet I’m calling the product function with a set of values (8 & 2). These are values of the variables ‘a’ and ‘b’ and they’re called as arguments to the function.

Conditional statements – if

Conditional statement is a set of rules performed if a certain condition is met. The ‘if’ statement is used to execute a block of code, only if the condition specified holds true.

What is JavaScript – if flowchart

To declare an if statement in JavaScript use the ‘if’ keyword. The syntax is:

if(condition) {
statement;
}

Now let’s look at an example:

let numbers=[1,2,1,2,3,2,3,1];
if(numbers[0]==numbers[2]) {
console.log('Correct!');
}

In the above example I’ve defined an array of numbers and then I’ve defined an if block. Within this block is a condition and a statement. The condition is ‘(numbers[0]==numbers[2])’ and the statement is ‘console.log(‘Correct!’)’. If the condition is met, only then the statement will be executed.

Conditional statements- Else if

Else statement is used to execute a block of code if the same condition is false.

What is JavaScript – Else-if flowchart

The syntax is:

if(condition) {
statement a;
}
else (condition) {
statement b;
}

Now let’s look at an example:

let numbers=[1,2,1,2,3,2,3,1];
if(numbers[0]==numbers[4] {
console.log("Correct!");
}
else {
console.log("Wrong, please try again");
}

In the above example, I’ve defined an if block as well as an else block. So if the conditions within the if block holds false then the else block gets executed. Try this for yourself and see what you get!

**Loops **

Loops are used to repeat a specific block until some end condition is met. There are three categories of loops in JavaScript :

  1. while loop
  2. do while loop
  3. for loop
While loop

While the condition is true, the code within the loop is executed.

What is JavaScript – while loop flowchart

The syntax is:

while(condition) {
loop code;
}

Now let’s look at an example:

let i=0;
while(i < 5) {
console.log("The number is " +i);
i++;
}

In the above example, I’ve defined a while loop wherein I’ve set a condition. As long as the condition holds true, the while loop is executed. Try this for yourself and see what you get!

Do while loop

This loop will first execute the code, then check the condition and while the condition holds true, execute repeatedly.

What is JavaScript – Do while loop flowchart

Refer the syntax to better understand it:

do {
loop code;
} while(condition);

This loop executes the code block once before checking if the condition is true, then it will repeat the loop as long as the condition holds true.

Now let’s look at an example:

do {
console.log("The number is " +i);
i++;
}
while(i > 5);

The above code is similar to the while loop code except, the code block within the do loop is first executed and only then the condition within the while loop is checked. If the condition holds true then the do loop is executed again.

For loop

The for loop repeatedly executes the loop code while a given condition is TRUE. It tests the condition before executing the loop body.

What is JavaScript – for loop flowchart

The syntax is:

for(begin; condition; step) {
loop code;
}

In the above syntax:

  • begin statement is executed one time before the execution of the loop code
  • condition defines the condition for executing the loop code
  • step statement is executed every time after the code block has been executed

For example:

for (i=0;i<5;i++) {
console.log("The number is " +i);
}

In the above example, I’ve defined a for loop within which I’ve defined the begin, condition and step statements. The begin statement is that ‘i=0’. After executing the begin statement the code within the for loop is executed one time. Next, the condition is checked, if ‘i<5’ then, the code within the loop is executed. After this, the last step statement (i++) is executed. Try this and see what you get!

Switch Case

The switch statement is used to perform different actions based on different conditions.

What is JavaScript – Switch case flowchart

Let’s look at the syntax for switch case:

switch(expression) {
case 1:
code block 1
break;
case 2:
code block 2
break;
default:
code block 3
break;
}

How does it work?

  • Switch expression gets evaluated once
  • Value of the expression is compared with the values of each case
  • If there is a match, the associated block of code is executed

Let’s try this with an example:

let games='football';
switch(games) {
case "throwball":
console.log("I dislike throwball!");
break;
case "football":
console.log("I love football!");
break;
case "cricket":
console.log("I'm a huge cricket fan!");
break;
default:
console.log("I like other games");
break;
}

In the above example the switch expression is ‘games’ and the value of games is ‘football’. The value of ‘games’ is compared with the value of each case. In this example it is compared to ‘throwball’, ‘cricket’ and ‘football’. The value of ‘games’ matches with the case ‘football’, therefore the code within the ‘football’ case is executed. Try this for yourself and see what you get!

With this, we come to the end of this blog. I hope you found this blog informative and I hope you have a basic understanding of JavaScript. In my next blog on JavaScript I’ll be covering in-depth concepts, so stay tuned.

Also, check out our video on JavaScript Fundamentals if you want to get started as soon as possible and don’t forget to leave a comment if you have any doubt and also, let us know whether you’d want us to create more content on JavaScript. We are listening!

Why ReactJS is better for Web Application Development?

Why ReactJS is better for Web Application Development?

Web Application Development is the point of contact for a business in today's digital era. It is important to choose the right platform for Web Application Development to build a high end Web

Web Application Development is essential for a business in today’s digital era. Finding the right platform for Web Application Development is important for building an effective Web Application that can enhance the overall customer engagement. Here’s what makes ReactJS a better option for building your next Web Application.