习题3-6

#include<stdio.h>#include<ctype.h>char up(char ch){if(ch>='a'&&ch<='z'){ch=toupper(ch);printf("%c\n",ch);return ch;}else{printf("%c\n",ch);}}int main(){char zifu;char jx;do{printf("请输入一个字母（大小写均可）：");scanf("%c",&zifu); up(zifu); printf("Are you continue?[y/n]\n"); jx=getchar();}while((jx=getchar())=='y');return 0;}