strange issue encountered while utilizing JavaScript's async/await syntax

Recently, I encountered an issue while trying to retrieve a random user from the randomuser API using code in my Vue frontend.

// Here is the structure of the API response
{ info: { // details omitted }, results: [ {//random user data} ] }

// This snippet of code works perfectly fine
async get_random_user() {
        const url = "https://randomuser.me/api/";
        const res = await fetch(url);
        const json_data = await res.json();
        const result = json_data.results[0];
        return result; 
    }

// However, this alternative approach throws an error - Uncaught (in promise) TypeError: Cannot read property '0' of undefined
async get_random_user() {
        const url = "https://randomuser.me/api/";
        const res = await fetch(url);
        const result = await res.json().results[0];
        return result; 
    }

I'm struggling to understand why the second function isn't working as expected. Any insights or solutions would be greatly appreciated. Thanks!

Answer №1

const data = await response.json().data[0];

By directly accessing the data property, you are taking a risk as it may not be available or processed yet. It's better to wait for the completion of response.json() method

UPDATE

There is no guarantee that the response.json() method will return any data, or even provide a proper response. Therefore, attempting to access the data prematurely is not advised.

The await keyword is being used on data[0], rather than on response.json().

In simpler terms, what you are essentially doing can be visualized like this:

data = response.json();
const result = await data[0];

This approach contains two logical flaws

Answer №2

When using the <code>await keyword, it expects a promise in return. However, the result of calling json() is a promise, but accessing json().results directly returns an object (which may be undefined initially). This is why await doesn't function as expected on that particular structure.

Answer №3

Verify that the results array in res.json() is not empty;

const firstResult = (await res.json()).results[0];

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