Updating Objects in State with React JS 🚗

In React, state is a crucial feature for managing data within a component. One common use case is updating objects within the state. In this tutorial, we will cover how to update objects in the state using React JS.

To get started, make sure you have a basic understanding of React components and state. If you’re new to React, I recommend checking out the official documentation for an overview of these concepts.

Let’s say we have a component that contains an object in its state like so:

import React, { Component } from 'react';

class MyComponent extends Component {
  state = {
    user: {
      name: 'John Doe',
      age: 30,
      email: 'johndoe@example.com'
    }
  }

  render() {
    const { user } = this.state;

    return (
      <div>
        <h1>{user.name}</h1>
        <p>{user.age} years old</p>
        <p>Email: {user.email}</p>
      </div>
    )
  }
}

export default MyComponent;

Now let’s say we want to update the email address of the user. We can achieve this by using the setState method and spreading the existing object in the state with the updated values.

Here’s how you can update the user’s email address:

class MyComponent extends Component {
  state = {
    user: {
      name: 'John Doe',
      age: 30,
      email: 'johndoe@example.com'
    }
  }

  updateUserEmail = (newEmail) => {
    this.setState({
      user: {
        ...this.state.user,
        email: newEmail
      }
    });
  }

  render() {
    const { user } = this.state;

    return (
      <div>
        <h1>{user.name}</h1>
        <p>{user.age} years old</p>
        <p>Email: {user.email}</p>
        <button onClick={() => this.updateUserEmail('newemail@example.com')}>
          Update Email
        </button>
      </div>
    )
  }
}

In the updateUserEmail method, we are using the setState method to update the email property of the user object in the state. We first spread the existing user object using the spread operator (...this.state.user) to maintain the other properties and then update the email property with the new value.

When the button is clicked, the updateUserEmail method is called with the new email address as an argument, which triggers a re-render of the component with the updated state.

This is how you can update objects in the state in React. Remember to use the setState method whenever you need to update the state to ensure that React properly re-renders the component with the updated data.