Arduino IDE preference setting

when i open arduino IDE,it will open the latest skech, it is convenient on personal computer,but I use it in classroom,when the next student open the IDE,the last student's skech will be opened. Is there anyway to shut this function ? I just need a complete empty sketch,even without "void setup()...."Is there a menu for editing preference.text?I just can not uderstand it .I don't know is it right to ask this quession here ,i don't know where to ask .So ,please reply ant help .Thanks

Some possible solutions are shared here:

If your solution involves getting the IDE to open the new sketch on startup, you can change the contents of that new sketch by editing the file examples/01.Basics/BareMinimum/BareMininum.ino under the Arduino IDE installation folder.

preferences.txt is a text file and can be edited with a simple text editor but I don't think that such an option exists. Even if it did then you would need to be able to disable access to the recent file list as well

The last opened sketch is stored in preferences.txt. So if you change that property then the Arduino IDE acts as it does on a fresh start and uses the File > New behavior.

As is explained later in the thread I linked, it turns out that there is a preference setting to make the preferences read-only, so the IDE is unable to write the latest sketch. Combine the two changes and the IDE will always open a new sketch on startup.

It's maybe not so desirable to not be able to save preferences though, in which case it might be preferable to take the other option of opening a specific sketch rather than just starting the IDE.