<cat>Dev.Lua</cat> <title>Concepts - Variadic Functions</title>⤶ <title>Concepts - Variable Argument Count (varargs)</title>⤶ # Variadic Functions Functions that take a variable amount of arguments are called `variadic`. <br/> ## Example The `print` function logs any number of values you supply it to the console. ```Lua print( 'These' , 'are' , 'a' , 'lot' , 'of' , 'arguments' , 1 , 2 , 3 ) ``` <br/> ## Declaration Variadic arguments can be declared with the name `...` at the ends of a function's list of arguments. ```Lua function ( first , second , ... ) ``` Calling the function with `( 1 , 2 , 3 , 4 )` results in: - `first` = `1` - `second` = `2` - `...` = `3 , 4` <br/> ## Usage You can use supply `...` as an argument to another function. ```Lua sum( 1 , 2 , ... , 5 ) -- Same as sum( 1 , 2 , 3 , 4 , 5 ) ``` <br/> ## Unpacking You can also create variadic arguments by <page text = 'unpacking' >Global.unpack</page> a table. ```Lua unpack({ 3 , 4 }) -- Same as `3 , 4` ``` <br/> ## Packing The opposite can be achieved by <page text = 'packing' >table.Pack</page> a table. ```Lua local arguments = table.Pack( ... ) -- Same as { 3 , 4 } ``` ```Lua local arguments = { ... } -- Shorthand Syntax ``` <br/> --- <br/> <example name = 'Summation' > <description> Adds up a variable numbers of values. </description> <code> function sum ( ... ) local total = 0 for _ , value in ipairs({ ... }) do total = total + value end return total end </code> <code name = 'Test' > print(sum(1,2,3)) </code> <output>6</output> </example> <br/> --- <br/> <example name = 'Average' > <description> Finds the mean of a variable numbers of values using the previous example's summation function. </description> <code name = 'Function' > function average ( ... ) return sum( ... ) / #{ ... } end </code> <code name = 'Test' > print(average(1,2,3)) </code> <output>2.0</output> </example>