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C++??????????????

??????????????????????C++???????????????????<fstream>????????????????????????C++?????????

1. ?????????

????????????????????????????????????????????????????????C++??<fstream>???????????????????ifstream????????ofstream????????

2. ??????????

?????????????????C++??????????????<fstream>??????????????

#include 
   
    #include 
    
     using namespace std;
    
   

???????<iostream>?<fstream>??????<iostream>????????????<fstream>??????????

3. ?????????

?????????????????????????C++????????????ifstream?ofstream?????????????????????

int main() {    ifstream in("E:\\data_in.txt");    ofstream out("E:\\data_out.txt");        if (!in.is_open()) {        cout << "Open file failure1" << endl;    }    if (!out.is_open()) {        cout << "Open file failure2" << endl;    }        // ??????    // ...        in.close();    out.close();    return 0;}

?????????????????in??????out????????"E:\\data_in.txt"?"E:\\data_out.txt"???????????????????????

4. ?????????

??????????????????????C++?????????????>>??????????????????????

int u, v, w;while (!in.eof()) {    in >> u >> v >> w;    cout << u << " " << v << " " << w << endl;    out << u << "--" << v << " " << w << endl;}

???????????while?????????????????in >> u >> v >> w??????????????u?v?w???????????????????????cout????out?

5. ?????

?????????????????????????????????????????

in.close();out.close();

6. ??????

??????????????C++?????

#include 
   
    #include 
    
     using namespace std;int main() {    ifstream in("E:\\data_in.txt");    ofstream out("E:\\data_out.txt");        if (!in.is_open()) {        cout << "Open file failure1" << endl;    }    if (!out.is_open()) {        cout << "Open file failure2" << endl;    }        int u, v, w;    while (!in.eof()) {        in >> u >> v >> w;        cout << u << " " << v << " " << w << endl;        out << u << "--" << v << " " << w << endl;    }        in.close();    out.close();    return 0;}
    
   

7. ??

??????????????????C++???????????????????????????????????????????????????????????????????????

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