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");}