Deep Dive into useState Hook

State in React JS

State in React.js is a transformative concept that enables the creation of interactive and responsive user interfaces. It allows components to track and update their own data, resulting in predictable application flows. By managing state, components can reflect real-time changes in the UI, enhancing the user experience.

State is essential for creating controlled components, ensuring accurate UI representation. It acts as a private memory accessible only to the component, making them more independent and facilitating easier testing. State also enables data retention across component lifecycles and page navigation, improving user experience by preserving the previous state.

Effectively handling state is crucial for developing stunning and user-friendly web applications. It empowers developers to manage and render applications in a way that produces optimal results. By leveraging state, React.js revolutionizes UI development and creates dynamic interfaces that respond seamlessly to user interactions.

useState Hook

React JS is a well known JavaScript open source library that is used for creating User Interfaces (UI). The features that it includes makes front end development more easy. One such feature that stands out as a powerful tool for managing state within functional components is useState. 

The useState hook is a crucial feature in React, allowing developers to effortlessly add and update state within functional components, eliminating the need for class components. 

In essence, useState enables the creation of state variables to store and modify data, accommodating changes over time driven by user input or dynamic information essential to the application.

How to use it?

Using the useState hook involves two steps.

Initially, we define a state variable using the useState function and we pass an initial value to the variable. React assigns the initial value to the variable when it is being changed for the first time 

Secondly, we can access and update the value of the state variable by using its name and a corresponding function that is provided by the useState hook.

const [count, setCount] = useState(0);

Array using useState Hook

Let us create a simple program that returns a random number when the button is clicked. It depicts how the state is managed in arrays by using useState Hook. 

  • The code showcases a functional component named ArrayStateExample that demonstrates the usage of the useState hook to manage an array state. It initializes an empty array and uses setItems to update it. On button click, addItem adds randomly generated numbers multiplied by 2 to the array using the spread operator.

String using useState Hook

Now let us take a look at how a state of a string can be managed by using useState Hook. In this program, the state of the string is updated in real-time, which means, as the user types, the updated string value is displayed on the screen. 

  • The code demonstrates a functional component called StringStateExample that utilizes the useState hook to manage a string state. It includes an input field reflecting the state value and an event handler function (handleChange) to update the state based on user input. The updated string value is displayed within a <p> element using {text}.

Object using useState Hook

The below example best depicts how the state of an object can be managed with the help of useState Hook. In this, users can input their Name and Age and the updated values are displayed below the input fields. 

  • The code illustrates a functional component called ObjectStateExample that employs the useState hook to manage an object state. Input fields are associated with properties of the object, and their values are displayed in <p> elements. The handleChange function updates the object state based on user input.


  • The data management is simplified by using this.
  • It constantly ensures the accuracy of the UI updates when the state is changed.
  • The data flow is foreseen so that it is easily understandable and to debug.


  • Additional complexities are introduced to the application architecture.
  • It can often increase the complexity of a simple application due to overuse.
  • It requires a lot of effort and learning 


State management in React is crucial for data management and synchronization. The useState hook simplifies state management in functional components, ensuring predictable data flow and scalability. 


Eesha Smitha Ravella

Sumit Dhakad