为什么有时候只要我第一次输错了，接下来都是输错的，怎么回事？？
#include<iostream.h>#include<string.h>int main(){ char a[7]; int i = 0; while(1) { memset(a,0,sizeof(a)); cout<<"请输入名字:"<<endl; for(i = 0;i < sizeof(a) - 1;i++) cin>>a[i]; a[i] = '\0'; if(!strcmp(a,"哈哈哈")) cout<<"哈哈哈\n"<<endl; else if(!strcmp(a,"哦哦哦")) cout<<"哦哦哦\n"<<endl; else cout<<"输入错误\n"<<endl; } return 0;}//C/C++ code#include<iostream>#include<string.h>#include <stdio.h>using namespace std;int main(){ char a[7]; int i = 0; while(1) { memset(a,0,sizeof(12)); cout<<"请输入名字:"<<endl; for(i = 0;i < sizeof(a) - 1;i++) cin>>a[i]; a[i] = '\0'; if(!strncmp(a,"哈哈哈",6)) cout<<"哈哈哈\n"<<endl; else if(!strncmp(a,"哦哦哦",6)) cout<<"哦哦哦\n"<<endl; else cout<<"输入错误\n"<<endl; while(getchar()!='\n'); // system("pause"); } return 0;}