C++ 如何写回刚刚读取的csv文件（c+；+；）？

我试图写回以前在程序中读取的csv文件。该程序当前看起来如下所示：

ifstream file;

    file.open ("file");

    e=0;

    while (file.good()) {

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var1[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var2[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var3[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var4[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var5[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var6[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var7[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var8[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var9[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var10[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var11[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var12[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var13[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var14[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var15[e]=infoc;

        ++e;

    }



    var1[e] = var1[e] + v1;
    var2[e] = var2[e] + v2;
    var3[e] = var3[e] + v3;
    var4[e] = var4[e] + v4;
    var5[e] = var5[e] + v5;
    var6[e] = var6[e] + v6;
    var7[e] = var7[e] + v7;
    var8[e] = var8[e] + v8;
    var9[e] = var9[e] + v9;
    var10[e] = var10[e] + v10;
    var11[e] = var11[e] + v11;
    var12[e] = var12[e] + v12;
    var13[e] = var13[e] + v13;
    var14[e] = var14[e] + v14;
    var15[e] = var15[e] + v15;
    //WRITE TO compYTD

    file.close();

ofstream ofile("file.csv"); 

for(int i = 0; i < e; i++)
   ofile << var1[i] << ", " << var2[i] << ", " << var3[i] << ", " << ... endl;

ofile.close();

---

在关闭文件之前，我想将新的计算变量写回文件，删除以前读取的所有内容。是否有一个函数允许我这样做？还有一个单独的函数允许我写回这个文件，添加到已经存在的行上吗？

我个人会关闭这个文件，然后使用如下方式写入新值：

ifstream file;

    file.open ("file");

    e=0;

    while (file.good()) {

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var1[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var2[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var3[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var4[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var5[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var6[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var7[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var8[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var9[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var10[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var11[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var12[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var13[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var14[e]=infoc;

        getline ( file, infor,',');
        istringstream (infor) >> infoc;
        var15[e]=infoc;

        ++e;

    }



    var1[e] = var1[e] + v1;
    var2[e] = var2[e] + v2;
    var3[e] = var3[e] + v3;
    var4[e] = var4[e] + v4;
    var5[e] = var5[e] + v5;
    var6[e] = var6[e] + v6;
    var7[e] = var7[e] + v7;
    var8[e] = var8[e] + v8;
    var9[e] = var9[e] + v9;
    var10[e] = var10[e] + v10;
    var11[e] = var11[e] + v11;
    var12[e] = var12[e] + v12;
    var13[e] = var13[e] + v13;
    var14[e] = var14[e] + v14;
    var15[e] = var15[e] + v15;
    //WRITE TO compYTD

    file.close();

ofstream ofile("file.csv"); 

for(int i = 0; i < e; i++)
   ofile << var1[i] << ", " << var2[i] << ", " << var3[i] << ", " << ... endl;

ofile.close();

---

您写入文件的任何内容现在都将位于文件末尾

我可以关闭我读取的文件并打开同一个备份文件进行写入吗？这会添加到文件中的现有数据上还是删除/覆盖它？除非您指定其他内容，否则流的

将创建一个新的空文件。这就是我提出这种方法的原因。但是，必须在读取所有数据后执行此操作。如果要同时读写，文件上必须有两个不同的名称[好的，在Unix/Linux/MacOS类型的操作系统中不严格要求，但依赖它确实不太重要]难道没有以附加模式打开文件之类的东西吗？是的，这会在文件的末尾添加新值。但是你的问题要求“删除旧文件并写入新值”，这就是我所描述的。。。“附加”模式将属于“指定其他内容”模式。啊，没有阅读“问题部分”的后半部分。请参见编辑（几秒钟后）。