Now before diving into the concepts of functional programming in React, let’s understand what is functional programming? The functional programming is a concept of creating pure functions for software logic. It avoids concepts of mutable data and a shared state as used in Object-oriented programming. The functional programming is based more on expressions and declarations rather the statements. The functional programming depends only on the arguments passed to the function.

 

Now let’s move to how functional programming is implemented in React

 

As we all know that React is one of the most sort out libraries in JavaScript for creating interfaces and heavily used by React JS Development Company. Its demand and success depends upon a lot of factors, but one of them is the clean and effective approach to programming. In React, everything in user Interface is a component. The components put together can create other components. So the application is itself is a component. This all gives an idea that React has an Object-oriented approach. The syntax for this is:-

 

 

But React hides a functional side also so let’s check how

 

Displaying an output

 

The main thing React component does is implement a render () method without which the component is not a React component. The render() method returns a React element so in other words, you could think it as React is requiring the component to have an output. So in turn makes you think of a component more in terms of a function rather than as an object. A component is something that returns an output on the basis of an input.

 

Now how can you implement React component as a function

 

 

Now this is a simple way to implement component

 

You can also pass arguments to it

 

 

Props Immutability

 

Now another way to think of a React component in a functional way is because of the props. You know props are immutable, you can read them, but you cannot change them. Making props immutable avoid many side effects since they play as an input argument to the component. The functional programming immensely emphasizes on the concept that the input argument should not be changed by a function. As this is the basic concept behind creating pure functions.

 

Data Flow

 

In React, the data flow happens from a higher up component towards the lower component and not vice versa. In other words, the React promotes the unidirectional data flow. So this concept doesn’t require a React JS Development Company to think React in terms of objects. This more emphasizes to think React in terms of a function.

 

The following code will help you understand the concept as described by the React Native Development Company.

 

 

At first it doesn’t seem a unidirectional flow

 

But now again consider the following version of the same code as depicted by React JS development Company

 

 

Now it should be clear that the component hierarchy is nothing but the composition of the function App() and Hello() and the unidirectional data flow.