Nil Values

2 min

In Lua, nil is used to represent non-existence or nothingness. It’s frequently used to remove a value in a table or destroy a variable in a script. For instance:

			
				Blanking out the value of a table
			
				Expected Output
			
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			local dictionaryTable = {
	Monday = 1,
	Tuesday = 2,
	Wednesday = 3
}
-- Output value of 'Tuesday' key
print(dictionaryTable.Tuesday)
-- Clear 'Tuesday' key
dictionaryTable.Tuesday = nil
-- Output value of key again
print(dictionaryTable.Tuesday)
		
			2
nil
		
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In Roblox, nil can also be used to clear an Instance object’s Instance/Parent|Parent value and effectively remove it from the game, although it may be possible to bring the object back. Consider this example:

			
				Sample use of "nil"
			
				Expected Output
			
				Expand
				
			-- Create a new brick
local part = Instance.new("Part")
-- Parent new part to the workspace, making it viewable
part.Parent = workspace 
wait(1)
-- Remove the part from view, but not from memory
part.Parent = nil
wait(1)
-- Part still exists because it's referenced by the variable 'part', so it can be returned to view
part.Parent = workspace 
wait(1)
-- Remove the part from view again
part.Parent = nil
-- Clear part reference so it gets picked up by the garbage collector
part = nil
		
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Tags:

lua
value
nil