va_arg returns the next unprocessed value from a variable argument list ap (which you must previously create with va_start). Specify the type for the value as the second parameter to the macro, type.
You may pass a va_list object ap to a subfunction, and use va_arg from the subfunction rather than from the function actually declared with an ellipsis in the header; however, in that case you may only use va_arg from the subfunction. ANSI C does not permit extracting successive values from a single variable-argument list from different levels of the calling stack.
There is no mechanism for testing whether there is actually a next argument available; you might instead pass an argument count (or some other data that implies an argument count) as one of the fixed arguments in your function call.### Returns
va_arg returns the next argument, an object of type type.
---
**Authoritative source**: BUSMASTER DITA help source `va_arg.dita`, compiled into `BUSMASTER.CHM` with the application.
