How To Use Named And Optional Parameters In C -

: Used to retrieve an indefinite number of arguments.

#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 How to use named and optional parameters in C

#define CREATE_WINDOW(...) create_window((WindowArgs){__VA_ARGS__}) // Now you can call it more like a native feature: CREATE_WINDOW(.width = 1024, .height = 768, .title = "Editor"); Use code with caution. Copied to clipboard 3. Alternative: Variadic Functions ( stdarg.h ) : Used to retrieve an indefinite number of arguments

Struct members not explicitly initialized are automatically set to zero or NULL by the compiler, effectively making them "optional". Example Implementation: Copied to clipboard 2

: 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)

The most common way to simulate named parameters is to pass a single struct to a function. By using C99 designated initializers, you can specify values for specific members by name.