Variadic Functions

Variadic functions accept a variable number of arguments, like printf, which can take any number of values depending on its format string. They are declared using an ellipsis (...) as the last parameter and accessed inside the function using macros from <stdarg.h>, such as va_start, va_arg, and va_end. Because the compiler cannot type-check variadic arguments the way it does regular parameters, mismatches between expected and actual argument types are a common source of bugs.