How to Use Axios with Async/Await to Fetch and Append Data in JavaScript

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How to Use Axios with Async/Await to Fetch and Append Data in JavaScript

In modern web development, handling asynchronous operations is a common challenge, especially when working with APIs. One common scenario developers encounter is fetching an object array with Axios, then using the returned data to make additional requests and manipulate the results.

The Problem

You may have encountered a situation where you want to fetch data from an API using Axios and then, for each item in the returned array, you want to make another API call to retrieve more information. However, you might face an issue where the data you are trying to append to your object isn't being added as expected.

Here is an example of what the initial code might look like:

[[See Video to Reveal this Text or Code Snippet]]

In this snippet, the issue arises because the return statement executes before the asynchronous operations within the map() method are completed. Therefore, the desired property (preview) does not get appended.

The Solution

To resolve this issue, it’s best to avoid using the map() function with asynchronous calls. Instead, you can use a for..of loop that allows you to wait for each asynchronous operation to complete before moving to the next iteration. Here's how it’s done:

Step-by-Step Code Implementation

Perform the initial Axios request.

Iterate over the results using a for..of loop.

Perform the second Axios request and append the data.

Return the modified results.

Here’s the updated code:

[[See Video to Reveal this Text or Code Snippet]]

Explanation of the Code

Axios Request: The first request fetches the initial data from the API.

Using for..of Loop: Instead of using map(), a for..of loop is used, which properly handles asynchronous calls by waiting for each iteration to complete before proceeding.

Appending Data: Here, we append the preview key to each ad object by accessing the relevant data from the second API call.

Return Statement: After all the asynchronous operations are completed, we return the modified results containing the appended preview keys.

Conclusion

Managing multiple asynchronous requests in JavaScript can be tricky. By utilizing a for..of loop instead of map, you can ensure your data is appended correctly without running into premature return issues. This streamlined approach enhances your ability to work with API data effectively, ensuring that your application's logic flows smoothly.