Troubleshooting: Issues with Parsing a JSON String from an API causing an Error (Error Message: Uncaught SyntaxError: Unexpected end of JSON input at JSON.parse (<anonymous>))

Question

Troubleshooting: Issues with Parsing a JSON String from an API causing an Error (Error Message: Uncaught SyntaxError: Unexpected end of JSON input at JSON.parse (<anonymous>))

I have been experimenting with fetching jokes using XMLHTTPRequest from a random joke generating API for practice.

Below is the code I am using:

<script>
    const xhr = new XMLHttpRequest();

    xhr.open('get', 'https://icanhazdadjoke.com/', true);
    xhr.setRequestHeader('Accept', 'application/json')
        const joke = JSON.parse(xhr.response)

    xhr.onload = function () {console.log(xhr.responseText)}
    xhr.send();

</script>

However, when I run this code, I encounter an error message: Uncaught SyntaxError: Unexpected end of JSON input at JSON.parse ().

Interestingly, if I use JSON.parse(xhr.response) and save it to a variable, the script works without any issues. Can anyone spot what I might be doing wrong in my code?

javascript json api parsing

Answer 1

Answer №1

When dealing with AJAX, it's important to remember that the response is received asynchronously. Make sure you handle the response in the onload handler as shown below:

const xhr = new XMLHttpRequest();

xhr.open('get', 'https://icanhazdadjoke.com/', true);
xhr.setRequestHeader('Accept', 'application/json');

xhr.onload = function () {
  const joke = JSON.parse(xhr.response);
  console.log(joke);
}
xhr.send();

Answer 2

When dealing with AJAX, it's important to remember that the response is received asynchronously. Make sure you handle the response in the onload handler as shown below:

const xhr = new XMLHttpRequest();

xhr.open('get', 'https://icanhazdadjoke.com/', true);
xhr.setRequestHeader('Accept', 'application/json');

xhr.onload = function () {
  const joke = JSON.parse(xhr.response);
  console.log(joke);
}
xhr.send();

Troubleshooting: Issues with Parsing a JSON String from an API causing an Error (Error Message: Uncaught SyntaxError: Unexpected end of JSON input at JSON.parse (<anonymous>))

Answer №1

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