for example the printf function can take different no of arguments:
printf("%d%d",x ,y); //here it takes only 3 arguments
printf("%d%d%d" ,a,b,c); // n here it takes 4 argumets

how can we declare user defined function like that, that can take many arguments,

i know when we use argv, argc as arguments in the main function. but i want a non main function behave like that.