c++ - 我应该如何更改此功能以删除 1 个特定条目(姓名和电话号码)，而不是整个记录(此功能当前正在执行)？

Question

void delete_record(){
char num[15];
int found=0;
ifstream delet("phone.dat",ios::binary);
ofstream ooo("temp.dat:",ios::binary);
cout<<"Enter number to delete:";
cin>>num;
delet.seekg(0,ios::beg);
while(delet.read((char*)&rec,sizeof(rec))){
if(strcmp(num,rec.phone)==0){
found=1;
cout<<"Name:"<<rec.name<<"\t"<<"Number:"<<rec.phone<<endl;
sleep(5);
cout<<"\nNumber Deleted:";
}
if(strcmp(num,rec.phone)!=0)
ooo.write((char*)&rec,sizeof(rec));
if(found==0)
cout<<"Record not found:";
ooo.close();
delet.close();
remove("phone.dat");
rename("temp.dat","phone.dat");
getch();
}

我正在尝试使用 cpp 和文件处理制作一个计算机化电话目录，我想制作一个函数来删除特定条目(姓名、相应的电话号码)而不是该特定文件中的全部数据。请帮助我这样做。

Answer 1

你在那里犯了几个错误。检查我在代码中的评论。

void delete_record() 
{
    char num[15];
    int found = 0;
    ifstream delet("phone.dat", ios::binary);
    ofstream ooo("temp.dat", ios::binary); // extra ':'
    cout << "Enter number to delete:";
    cin >> num;
    delet.seekg(0, ios::beg);
    while (delet.read((char*)&rec, sizeof(rec)))
    {
        found = 0; // set back to 0
        if (strcmp(num, rec.phone) == 0) 
        {
            found = 1;
            cout << "Name:" << rec.name << "\t" << "Number:" << rec.phone << endl;
            sleep(5);
            cout << "\nNumber Deleted:";
        }

        if (strcmp(num, rec.phone) != 0)
            ooo.write((char*)&rec, sizeof(rec));

        if (found == 0)
            cout << "Record not found:";
    }
    // this has to be out of while scope
    ooo.close();
    delet.close();
    remove("phone.dat");
    rename("temp.dat", "phone.dat");
    getch();
}

还有我的建议:

• 学习如何使用调试器逐步调试和检查代码。
• 写出漂亮的代码。如果您可以轻松阅读它，那么您可以更快地找到错误(例如，应该在 while 之外的代码)