可变参数模拟实现printf

#include<stdio.h> #include<stdarg.h> #include<assert.h> void myprintf(const char *s1, ...) { assert(s1 != NULL); va_list arg; char c; char ch; char *str; int temp; va_start(arg, s1); while (c=*s1++) { switch (c) { case'%' : break; case 'c': ch = va_arg(arg,int); putchar(ch); break; case 's': str = va_arg(arg, char *); fputs(str, stdout); break; case 'd': temp = va_arg(arg, int); printf("%d",temp); break; default: putchar(c); } } va_end(arg); } int main() { char *s = "aaaaaa"; char c = 'b'; int i = 1997; myprintf("%s\n %c \n%d", s, c, i); system("pause"); }