How does MapInfo handle button identifiers?

Question

As in create button pad statement:

Create ButtonPad { title_string | ID pad_num } As
        button_definition [ button_definition ... ] 
    [ Title title_string ]
    [ Width w ]
    [ Position ( x, y ) [ Units unit_name ] ]
    [ ToolbarPosition ( row, column ) ]
    [ { Show | Hide } ] 
    [ { Fixed | Float } ]

And In create button

{ PushButton | ToggleButton | ToolButton }
    Calling { procedure | menu_code | OLE methodname | DDE server, topic }
    [ ID button_id ]
    [ Icon n [ File file_spec ] ]
    [ Cursor n [ File file_spec ] ]
    [ DrawMode dm_code ] 
    [ HelpMsg msg ]
    [ ModifierKeys { On | Off } ] 
    [ Enable ] [ Disable ]
    [ Check ] [ Uncheck ]

As for my question the default button may already have ID so how would we know that ID is unique.

Answer 1

If you want to see what IDs MapInfo assigns to menus, buttonpads and buttons, open the file MENU.def up in a text editor (Notepad is fine, I use Notepad++). The file is installed to the following location:

C:\Program Files\MapInfo\MapBasic (assuming you installed MapBasic in the default location).

This will give you all of the IDs of the menu commands and buttons that MapInfo uses.