In Java, checking if variable is initialized with if x == null give me variable might not have been initialized error

I want to check if a variable is initialized before using it.

        java.io.File yDriveFolder;

        //move files to temp folder 
        for(int i=0; i<filesForDocument.length; i++){
          ...
          yDriveFolder = new java.io.File(yDrivePath + "/");
          ...
        }
        //delete source folder when it is done  
        if(filesForDocument.length> 1){
          if(yDriveFolder != null){
            yDriveFolder.delete();
          }
        }

error: variable yDriveFolder might not have been initialized

How should I check if a variable is initialized before using it?

>Solution :

Write something like java.io.File yDriveFolder = null; Then the compiler knows you know it is not initialized.