How To Use Named And Optional Parameters In C ❲Direct ✭❳
#include // Define a struct to hold "parameters" typedef struct { int width; int height; const char *title; // Optional (defaults to NULL) } WindowArgs; void create_window(WindowArgs args) { printf("Window: %s (%dx%d)\n", args.title ? args.title : "Untitled", args.width, args.height); } int main() { // Named and optional call using a compound literal create_window((WindowArgs){.width = 800, .height = 600}); // Changing order and including all fields create_window((WindowArgs){.title = "Game", .height = 1080, .width = 1920}); return 0; } Use code with caution. Copied to clipboard 2. Enhancing with Macros for Cleaner Syntax
Struct members not explicitly initialized are automatically set to zero or NULL by the compiler, effectively making them "optional". Example Implementation: How to use named and optional parameters in C
: The caller must still know the order or use "sentinel" values (like NULL ) to mark the end of the argument list. Summary of Techniques Supports Named? Supports Optional? Standard Requirement Standard Positional Struct + Initializer Yes (defaults to 0) C99 or later Variadic Macros Yes (via struct) C99 or later stdarg.h Yes (manual) #include // Define a struct to hold "parameters"
Standard C (ANSI C, C99, C11, etc.) does not natively support named or optional parameters in the way languages like C# or Python do. However, you can emulate this behavior by using a combination of , designated initializers , and variadic macros . 1. Using Structs and Designated Initializers Enhancing with Macros for Cleaner Syntax Struct members