Ask AI: Unexpected token '<', " <!doctype "... is not valid JSON what does it mean.

The error message "Unexpected token '<', ' <!doctype '... is not valid JSON" typically means that you are trying to parse or process an HTML response as if it were JSON data. This usually happens when an API request returns an HTML error page (like a 404 Not Found or 500 Internal Server Error page) instead of the expected JSON response. Here are a few steps you can take to troubleshoot and resolve this issue: 1. **Check the API Endpoint:** Ensure you are making a request to the correct API endpoint and that the endpoint URL is correct. 2. **Inspect the Response:** Log the response you are receiving before trying to parse it as JSON. This will help you see if you're getting an HTML response and what it says. ```javascript fetch('your-api-endpoint') .then(response => response.text()) // Use .text() for raw response .then(data => { console.log(data); // Inspect the response content // If it's valid JSON, parse it with JSON.parse(data) or response.json() }) .catch(error => console.error('Error:', error)); ``` 3. **Check the HTTP Status Code:** Inspect the status code of the response to ensure it's a successful response (usually a status code in the 200 range). ```javascript fetch('your-api-endpoint') .then(response => { if (!response.ok) { throw new Error('Network response was not ok ' + response.statusText); } return response.json(); }) .then(data => { console.log(data); // Process your JSON data here }) .catch(error => console.error('Error:', error)); ``` 4. **Handle Errors Gracefully:** Implement error handling to manage cases where the API returns an error page. You might want to show an error message to the user or retry the request. ```javascript fetch('your-api-endpoint') .then(response => { if (response.headers.get('content-type')?.includes('application/json')) { return response.json(); } else { throw new Error('Response is not JSON'); } }) .then(data => { console.log(data); // Process your JSON data here }) .catch(error => console.error('Error:', error)); ``` By following these steps, you should be able to identify the root cause of the issue and handle it correctly.