Describe the problem that you experienced

The filter input should be empty by default, but it contains 'undefined'.

Enter the URL of the topic with the problem

https://angular.dev/api

Describe what you were looking for in the documentation

No response

Describe the actions that led you to experience the problem

No response

Describe what you want to experience that would fix the problem

No response

Add a screenshot if that helps illustrate the problem

If this problem caused an exception or error, please paste it here

If the problem is browser-specific, please specify the device, OS, browser, and version

Provide any additional information here in as much as detail as you can