一个奇怪的问题
在tc下编程遇到一奇怪问题用scanf("%c",ch);或getchar()时第一次运行根本没有让输入什么东西如果连续打两个才会有一次让输入的提示谁知道怎么回事
#include <stdio.h> struct studen {int xuehao; char name[20]; char kecheng[20]; int nian; }xuesheng[5]; void chushihua(void); void nian(void); void id(void);
main() { char ch; chushihua(); while(1) { clrscr(); printf("\nA.yong nian fen cha xun xin xi.\nB.yong ID cha xun xin xi.\nC.tui chu xi tong.\nqing shu ru xuan xiang hui che que ren:"); scanf("%c",&ch); switch (ch) { case 'a': case 'A': nian(); break; case 'b': case 'B': id(); break; case 'c': case 'C': exit(0); break; default: printf("\nshu ru cuo wu qing chong xin shu ru "); } } } void chushihua() { int i; clrscr(); for(i=0;i<5;i++) { printf("\nshu ru di %d ge xue sheng de xue hao :",i+1); scanf("%d",xuesheng[i].xuehao); printf("\nshu ru di %d ge xue sheng de xing ming :",i+1); scanf("%s",xuesheng[i].name); printf("\nshu ru di %d ge xue sheng de ke cheng :",i+1); scanf("%s",xuesheng[i].kecheng); printf("\nshu ru di %d ge xue sheng ru xue nian fen:",i+1); scanf("%d",xuesheng[i].nian); } return; } void nian() { int ntem,i,x=1; char chtem; clrscr(); printf("\nshu ru yao cha xun de nian fen"); scanf("%d",&ntem); printf("\ncha xun jie gu"); for(i=0;i<5;i++) { if(xuesheng[i].nian==ntem) { printf("\n%d.xue sheng xue hao :%d",x,xuesheng[i].xuehao); printf("\n xue sheng ming zi :%s",xuesheng[i].name); printf("\n xue sheng ke cheng :%s",xuesheng[i].kecheng); printf("\n xue sheng ru xue nian fen:%d",xuesheng[i].nian); x++; } } printf("\nji xu qing an \"y\"tui chu qing an\"n\" "); scanf("%c",&chtem); if(chtem=='y'||chtem=='Y') return; else exit(0); } void id() { int xtem,i,x=1; char chtem; clrscr(); printf("\nshu ru yao cha xun de nian fen"); scanf("%d",&xtem); printf("\ncha xun jie gu"); for(i=0;i<5;i++) { if(xuesheng[i].xuehao==xtem) { printf("\n%d.xue sheng xue hao :%d",x,xuesheng[i].xuehao); printf("\n xue sheng ming zi :%s",xuesheng[i].name); printf("\n xue sheng ke cheng :%s",xuesheng[i].kecheng); printf("\n xue sheng ru xue nian fen:%d",xuesheng[i].nian); x++; } } printf("\nji xu qing an\"y\"tui chu qing an\"n\""); scanf("%c",&chtem); if(chtem=='y'||chtem=='n') return; else exit(0); }
