Unexpected Null Behavior When Using JSON Encode with PHP Arrays in PHP 8.0
I've searched everywhere and can't find a clear answer. This might be a silly question, but I'm working on a project and hit a roadblock... I'm facing an issue when trying to encode an array to JSON in PHP 8.0, where some of the values are unexpectedly returning as `null`. The array structure is complex, containing nested arrays and objects, and I'm using the `json_encode` function. Here's a simplified version of the array I'm working with: ```php $data = [ 'user' => [ 'id' => 1, 'name' => 'John Doe', 'preferences' => [ 'notifications' => true, 'theme' => null, ], ], 'posts' => [ [ 'title' => 'First Post', 'content' => 'This is the content.', 'tags' => ['php', 'web development'], ], [ 'title' => 'Second Post', 'content' => null, 'tags' => ['laravel', 'api'], ], ], ]; ``` When I run `json_encode($data)`, I get the following output: ```json {"user":{"id":1,"name":"John Doe","preferences":{"notifications":true,"theme":null}},"posts":[{"title":"First Post","content":"This is the content.","tags":["php","web development"]},{"title":"Second Post","content":null,"tags":["laravel","api"]}]} ``` The `content` key for the second post is returned as `null`, which is expected since the value is explicitly set to `null`. However, I'm concerned about how the `theme` key within the `preferences` array is also being encoded as `null`. I was under the impression that if I wanted to exclude `null` values from the JSON output, I could use the `JSON_FORCE_OBJECT` flag like this: ```php $json = json_encode($data, JSON_FORCE_OBJECT); ``` But this doesn't seem to change the output. I also tried using `JSON_PRESERVE_ZERO_FRACTION`, but that didn't help either. My goal is to produce JSON without any `null` values, but I want to keep the structure intact. Any tips on how to achieve that while still preserving the data hierarchy effectively? Am I missing something, or is there a better approach to handle this in PHP 8.0? My development environment is Linux. I'd really appreciate any guidance on this. How would you solve this? This is happening in both development and production on Ubuntu 20.04. Any advice would be much appreciated.