filesize() return 0 while trying to fread() a json file

Details about my Goal :

I Wanted to combine a new Data comes from my mobile application with the data which is stored on a Json file and used that data to process user things but any data greater than 1KB starts the error .

Error Codes : PHP Warning: fread(): Length parameter must be greater than 0

I’ve make sure the file size is not 0, its 4.89KB !

The Code :

        $RawFile = fopen($FileName, "w+") or die("Unable to open file!");
         $IsiFile = fread($RawFile,filesize($FileName));
          $DataFile = json_decode($IsiFile, true);
           $DataPengguna = $DataFile[$UserID];
           $DataOverwrite = $DataPengguna . '' . $tulisan;
          $DataFile[$UserID] = $DataOverwrite;
         fwrite($RawFile, json_encode($DataFile));
        fclose($RawFile);

The contents of Json file : Prnt.sc/r9hek8

Mean of the Variable in my code :

$IsiFile = The Json

$DataFile = I prefer Array to access the data

$DataPengguna = The user Data [Every user have their own UserID]

$DataOverwrite = Combine the old already stored data with the new data

Put it back on the array and do fwrite(), then closed the file

Answer

This is a place of a logical error: fopen($FileName, "w+")
The “w+” mode always drops a file content. Just use “r+” mode and if you need write to file later, reopen it with “w+” mode.