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ReactjJS Functional Components & When to Use Them

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ReactjJS Functional Components & When to Use Them

Imagine if there was a way to help you code easily and test effectively while achieving better performance? This is every programmer’s dream, am I not right? Well, react.js has functional components that help us code with ease and give amazing results in return. Here we will understand everything there is to know about React.js functional components. To learn about functional component and their benefits, you will need to have adequate knowledge about the basics of React. Additionally, knowing ES6 would be advantageous.

What are React.js functional components?

In React.js there are two main types of components used by programmers, class components and functional components. Class components involve the use of ES6 classes, while functional components make use of functions. A functional component has only one constraint that has to take props as an argument and it should return a valid JSX. On the other hand, class components have to use the render method. Functional components do not have state and lifecycle methods like class components. This is the reason why they are also known as stateless components. 

Why should you use React.js functional components?

You must be wondering how the lack of state and lifecycle methods can be advantageous? Well, here are some of the key reasons why you should be using functional components over classes in React.js:

1. Makes code more readable

The biggest advantage of the functional component is that they have your code easily and also make your program easy to read and understand for others. More time is utilized in reading than in writing the code hence programmers should ensure the code is easy to read so that other people can also make their contribution effectively.

Functional components can not have hidden inputs nor modify a hidden state. Additionally, the use of prop helps to understand what is getting used in the functional component. This helps the reader understand where things go and come from.

2. Easy to test

It is easy to test components that do not have any side effects or hidden states. Furthermore, for every input in functional components, there is only one output. This makes testing of functional components very easy and you will not need to rely on any state manipulation or external testing libraries.

3. Yields better performance 

As there are no states or lifecycle methods in functional component, the overload created by lifecycle events are eliminated hence this avoids unnecessary memory allocation and checks. Additionally, functional components require fewer lines of code and faster bundles. All these points drastically optimize the performance giving us better and faster results.

4. Debugging is a piece of cake

Functional components make use of props which result in only one output makes debugging easy for programmers. There is no requirement to continuously check or log the state of the component in order to understand what is happening. 

5. Reducing Coupling Factor

Coupling states the degree of dependency between different entities thereby helping us get a clear understanding of how clean any code is. If the code has low coupling, then it means that we can make changes in one area without affecting the other areas of the code. This helps in the maintenance of the code. The constraint of the functional component in react.js restricts us to confine all the logic within the function hence giving us a low coupling factor.

When to avoid the use of React.js functional components?

Functional components have their pros but also have some cons at the same time. If functional components were the perfect option for all situations then there would be no need for class components in react.js. But that is not the case. Here are some of the cons of using them:

1. Complex syntax

The syntax of functional components is a little different and hard to grasp if you have been working with classes or object-oriented concepts. In a class, you need to declare the render function but in function, you need to pass props as an argument. These changes might be difficult to adapt to while trying to learn about react.js and concepts related to it.

2. Performance Optimization

In reality, choosing a certain type of component will not boost your performance. However, as functional components do not use life cycle and state methods, you will not have access to methods like PureComponent() and shouldComponentUpdate(). This might cause an inconvenience to optimize the code for better performance.


We understand what are functional components, their benefits, and their limitations. Hope that all the doubts and queries you had about react.js functional components have been catered to. Remember using a certain component does not change the performance of your project but the logic you use does. Do not forget to check out Codedamn’s blogs and courses if you want to know more about other concepts in React and Web development.

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