c++ - 添加到文件而不删除里面的内容

Question

我正在编写一个代码，该代码从用户那里获取一些输入并将其存储在一个文件中。我的代码应该保留旧数据并添加新数据，但是每次我运行代码时，文件中的旧数据都会被新数据替换。

if(input == 1){
             outFile.open("personnel2.dat");
             int numRecords = 0;
             do{
                 cout << "#1 of 7 - Enter Employee Worker ID Code(i.e AF123): ";
                 cin >> id;
                 cout << "#2 of 7 - Enter Employee LAST Name: ";
                 cin >> lastN;
                 cout << "#3 of 7 - Enter Employee FIRST Name: ";
                 cin >> firstN;
                 cout << "#4 of 7 - Enter Employee Work Hours: ";
                 cin >> workH;
                 cout << "#5 of 7 - Enter Employee Pay Rate: ";
                 cin >> payRate;
                 cout << "#6 of 7 - Enter FEDERAL Tax Rate: ";
                 cin >> federalTax;
                 cout << "#7 of 7 - Enter STATE Tax Rate: ";
                 cin >> stateTax;
                 outFile << id << " " << lastN << " " << firstN << " " << workH << " " << payRate << " "
                         << federalTax << " " << stateTax << "\n";
                 numRecords++;
                 cout << "Enter ANOTHER Personnel records? (Y/N): ";
                 cin >> moreRecords;
             }while(moreRecords != 'N' && moreRecords != 'n');

             outFile.close();
             cout << numRecords << " records written to the data file.\n";

             }

标签： c++

Answer 1

改变outFile.open("personnel2.dat");

到

outFile.open("personnel2.dat", std::fstream::app);

假设您使用的是fstream::open().