I3wm get window class

stay i3wm If you want to fix a program in a workspace The following settings can be set when opening

# open virtual box Go straight to 10 Desktop 
assign [class="(?i)virtual"] $ws10

Here we need class This attribute matches . So here comes the question , This class How to get the properties ？
Use xprop To get

# Usage method
You just need to be in the same workspace Open your application and terminal in , Input in the terminal xprop Here your mouse will turn into a crosshair , Click on your application to get the information of the window .

The final contents are as follows ：

WM_CLASS(STRING) = "jetbrains-idea", "jetbrains-idea"

Reference resources

https://www.tuxtips.info/linux/how-to-find-applications-window-class-in-i3-window-manager