Concepts - nil Value
nil Value
nil
is Lua's representation of empty data. Unset variables and non-existent table keys will be nil. This will be treated as false in if-statement contexts, but is not equal to false.
See also NULL
Example
Output: nil
false
false
true
true
nil
b = bar
Application in VGUI
You can use nil to make some VGUI element transparent.