nil
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.
Example:
print(nil)
print(nil == 0)
print(nil == 1)
print(nil == nil)
print(!nil) --because nil can be treated like a false boolean in some cases, "not nil" will equal true
local myEmptyVariable --a variable with nothing in it (a 'nil' value)
print(myEmptyVariable)
local myTable = {a="foo", b="bar"}
myTable["a"] = nil --setting a value in a table to nil effectively erases it from the table
PrintTable(myTable)
Output:
nil
false
false
true
true
nil
b = bar
Application in VGUI
You can use nil to make some VGUI element transparent.
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