React Fetching Data Using Fetch Api And Axios Complete Guide

1. What is the difference between Fetch API and Axios in React?

Fetch API: It's a built-in JavaScript API provided by modern browsers to make network requests. It returns promises and uses the fetch() function which can be utilized for sending HTTP or HTTPS requests.

Axios: A popular third-party library for making HTTP requests from node.js or XMLHttpRequests from the browser. It supports Promises, which makes it easy to use in React applications. Unlike Fetch API, Axios automatically transforms JSON data.

2. How do I use the Fetch API to get data from an external JSON API in React?

import { useState, useEffect } from 'react';

function FetchData() {
  const [data, setData] = useState([]);
  
  useEffect(() => {
    fetch('https://api.example.com/data')
      .then(response => response.json())
      .then(data => setData(data))
      .catch(error => console.error('Error fetching data:', error));
  }, []);

  return (
    <div>
      {/* Render your data here */}
      {data.map(item => 
        <div key={item.id}>{item.name}</div>
      )}
    </div>
  );
}

export default FetchData;

Here, you're using the useEffect hook to trigger a fetch request after the component mounts, and the useState hook to store the fetched data.

3. Can I use Axios in React instead of the Fetch API? How?

First, install Axios:

npm install axios

Then, you can fetch data using Axios as follows:

import React, { useState, useEffect } from 'react';
import axios from 'axios';

function FetchAxiosData() {
  const [data, setData] = useState([]);

  useEffect(() => {
    axios.get('https://api.example.com/data')
      .then((response) => setData(response.data))
      .catch((error) => console.error('Error fetching data:', error));
  }, []);

  return (
    <div>
      {/* Render your data here */}
      {data.map(item => 
        <div key={item.id}>{item.name}</div>
      )}
    </div>
  );
}

export default FetchAxiosData;

The get() method in Axios automatically parses JSON from the responses.

4. When should I use Fetch API and when should I consider Axios?

Use Fetch API when:

• You are working with a modern browser and prefer using native JavaScript functionality.
• You want to have fine-grained control of the request process.

Consider Axios when:

• You need more features such as automatic JSON transformation, built-in support for canceling requests, and request and response interceptors.
• You want cleaner code and better handling of cross-browser compatibility since Axios manages it internally.

5. How do I handle errors more gracefully using Axios in React?

Axios has a catch method that catches all network errors or HTTP error responses (status codes 4xx and 5xx).

import React, { useState, useEffect } from 'react';
import axios from 'axios';

const FetchErrorHandlingData = () => {
  const [error, setError] = useState(null);
  const [data, setData] = useState([]);

  useEffect(() => {
    axios.get('https://api.example.com/data')
      .then((response) => setData(response.data))
      .catch((err) => {
        // Network error
        if (!err.response) {
          setError("Network Error");
        } else {
          // HTTP error
          setError(err.response.status + ": " + err.response.statusText);
        }
      });
  }, []);

  // Render logic
}

export default FetchErrorHandlingData;

6. How can I add headers to my Axios request?

Pass the headers object as the second argument within a config object in your request:

axios.get('/your-url-here', {
  headers: {
    'Content-Type': 'application/json',
    'Authorization': 'Bearer YOUR_ACCESS_TOKEN'
  }
})
.then(response => ...)
.catch(error => ...);

7. How can I make POST requests using both the Fetch API and Axios?

Using Fetch API:

fetch('https://api.example.com/data', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    title: 'foo',
    body: 'bar',
    userId: 1
  })
})
.then(response => response.json())
.then(data => console.log(data))
.catch(error => console.error('Error:', error));

Using Axios:

axios.post('https://api.example.com/data', {
  title: 'foo',
  body: 'bar',
  userId: 1
})
.then(response => console.log(response.data))
.catch(error => console.error('Error:', error));

Axios automatically converts the data to JSON.

8. Is there a way to add timeouts in network requests when using either Fetch API or Axios?

Fetch API: Fetch does not support timeout natively, but you can combine fetch with a promise-based timeout solution like so:

const fetchDataWithTimeout = async (url, ms) => {
  const controller = new AbortController();
  const signal = controller.signal;

  setTimeout(() => controller.abort(), ms);

  try {
    let response = await fetch(url, { signal });
    let data = await response.json();
    console.log(data);
  } catch (err) {
    if (err.name === 'AbortError') {
      console.log('Timeout');
    }
  }
};

fetchDataWithTimeout('https://api.example.com/data', 5000); // timeout after 5 seconds

Axios: Axios provides a built-in timeout configuration option:

axios.get('https://api.example.com/data', {
  timeout: 5000 // timeout after 5 seconds
})
.then(response => console.log(response.data))
.catch(error => {
  if (error.code === "ECONNABORTED") {
    console.log('Timeout');
  }
});

9. How can I perform async/await syntax while fetching using the Fetch API and Axios in React?

Fetch API with async/await:

import { useState, useEffect } from 'react';

function FetchAsyncData() {
  const [data, setData] = useState([]);

  useEffect(() => {
    async function getData() {
      try {
        const response = await fetch('https://api.example.com/data');
        const result = await response.json();
        setData(result);
      } catch (err) {
        console.error('Error:', err);
      }
    }

    getData(); // Invoke immediately
  }, []);

  // render logic
}

Axios with async/await:

import React, { useState, useEffect } from 'react';
import axios from 'axios';

const FetchAxiosAsyncData = () => {
  const [data, setData] = useState([]);

  useEffect(() => {
    const getData = async () => {
      try {
        const response = await axios.get('https://api.example.com/data');
        setData(response.data);
      } catch (error) {
        console.error("Error:", error);
      }
    };

    getData(); // Invoke immediately
  }, []);

  // render logic
}

export default FetchAxiosAsyncData;

10. Is there any advantage in using one over the other (Fetch vs Axios) for fetching data in React?

While the Fetch API is native and lightweight, Axios offers several advantages:

• Easier to work with, especially for handling JSON data since it parses it automatically.
• Comprehensive error handling that differentiates network errors and HTTP errors.
• Ability to configure defaults and create reusable instances.
• Built-in support for request cancellation, which can prevent memory leaks.
• Interceptors to allow modifying or observing requests globally.

However, if you're looking for a pure JavaScript solution with no external dependencies or need advanced control over requests, the Fetch API might be more appropriate. For most cases, Axios simplifies the process of data fetching in React applications.