<function name="upvaluejoin" parent="debug" type="libraryfunc"> <description> <removed>This function was removed due to security concerns.</removed> Make the n1-th upvalue of the Lua closure f1 refer to the n2-th upvalue of the Lua closure f2. Makes an upvalue of `func1` refer to an upvalue of `func2`. Both functions provided must be Lua-defined, otherwise an error is thrown. </description> <realm>Shared and Menu</realm> <args> <arg name="f1" type="function"></arg> <arg name="n1" type="number"></arg>⤶ <arg name="f2" type="function"></arg> <arg name="n2" type="number"></arg>⤶ <arg name="func1" type="function"></arg> <arg name="upvalueIndex1" type="number">The index of the upvalue in `func1`.</arg>⤶ <arg name="func2" type="function"></arg> <arg name="upvalueIndex2" type="number">The index of the upvalue in `func2`.</arg>⤶ </args> </function> ⤶ ⤶ <example>⤶ <description>Example code to demonstrate how the function works.</description>⤶ <code>⤶ local x = 5⤶ local y = 8⤶ ⤶ -- 1st upvalue refers to 'x' local variable⤶ -- 2st upvalue refers to 'y' local variable⤶ local function Add()⤶ return x + y⤶ end⤶ ⤶ local z = 12⤶ ⤶ -- 1st upvalue refers to 'z' local variable⤶ -- 2st upvalue refers to 'x' local variable⤶ local function Subtract()⤶ return z - x⤶ end⤶ ⤶ print(Add()) -- Expected: 13⤶ ⤶ --[[⤶ Makes the 2nd upvalue of 'Add' refer to the 1st upvalue of 'Subtract'.⤶ ⤶ The 2nd upvalue of 'Add' is stil 'y', but the function will now use the⤶ the 1st upvalue of 'Subtract' in its place.⤶ ]]⤶ debug.upvaluejoin(Add, 2, Subtract, 1)⤶ ⤶ print(Add()) -- Expected: 17⤶ ⤶ -- Show that debug.upvaluejoin did not modify the values of the variables⤶ print(x, y, z) -- Expected: 5, 8, 12⤶ </code>⤶ <output>⤶ ⤶ ```⤶ 13⤶ 17⤶ 5 8 12⤶ ```⤶ ⤶ </output>⤶ ⤶ </example>