I want to display the node count number (automatically allocated to each node by YEd) in the node.

Question

Each node in YEd is automatically allocated a "node-number" by YEd.  This number you can see if you export to the *.tgf format and openth file in an text editor of choice, e.g. Notepad.  It is the numbers after the "#" in the "*.tgf" file which shows which nodes are linked to which nodes.

I want to display this number in the node.

Answer 1

The numbers as you see them in the .tgf file are more or less an artifact of the TGF file export. If you save the same diagram to a .gml or a .graphml file, you can see that the identifiers of the nodes in both these files use different naming schemes.