#### A.2.2 How Variadic Functions are Defined and Used ¶

Defining and using a variadic function involves three steps:

- Define the function as variadic, using an ellipsis (‘`…`’) in the argument list, and using special macros to access the variable arguments. See Receiving the Argument Values.
- Declare the function as variadic, using a prototype with an ellipsis (‘`…`’), in all the files which call it. See Syntax for Variable Arguments.
- Call the function by writing the fixed arguments followed by the additional variable arguments. See Calling Variadic Functions.