In array to get rid of string()?

The script from the folder take all the files with the file extension .json, if it's really .json, it removes the file extension, and writes the name (user) into an array $data['users']
And here came the problem, in the mountains there were some string(), here is an example answer:

array(2) { [0]=> string(11) "1enderstore" [1]=> string(5) "sport" }

Output via var_dump()
var_dump($data['users']);

How to convert to a normal array? Namely in array(2) { [0]=> "1enderstore" [1]=> "sport" }

And the most interesting, if you convert to json (var_dump(json_encode($data['users']));), then the answer is:
string(23) "["1enderstore","sport"]"