Question

#include<iostream>
#include<fstream>
#include<string>
#include<iomanip>
using namespace std;
class InsurancePolicy
{
    friend fstream&  operator<<(fstream&, InsurancePolicy);
    friend istream& operator>>(istream&, InsurancePolicy&);
private:
    int policyNum;
    string lastName;
    int value;
    int premium;
};
fstream& operator<<(fstream& out, InsurancePolicy pol)
{
    out << pol.policyNum << " " << pol.lastName << " " << pol.value << " " << pol.premium << endl;
    return out;
}
istream& operator>>(istream& in, InsurancePolicy& pol)
{
    in >> pol.policyNum >> pol.lastName >> pol.value >> pol.premium;
    return in;
}
int main()
{
    ofstream outfile;
    outFile.open("Policy.txt");
    Policy aPolicy[10];
    for (int count = 0; count < 10; ++count)
    {
        printf("Enter the policy number, the holder's last name, the value, and the premium.");
        cin >> aPolicy[count];
        outfile << aPolicy[count] << endl;
    }

} 该程序应接受键盘中的值并将其打印到文件中。但是，它给出了一堆语法错误。

严重性码描述项目文件线镇压国错误 C2065 ＆＃39; outFile＆＃39;：未声明的标识符 Project6 c：\ users \ preston freeman \ source \ repos \ jave.cpp 39

错误 C2228 左边的＆＃39; .open＆＃39;必须有class / struct / union Project6 c：\ users \ preston freeman \ source \ repos \ jave.cpp 39

错误 C2065 ＆＃39;政策＆＃39;：未声明的标识符 Project6 c：\ users \ preston freeman \ source \ repos \ jave.cpp 40

错误 C2146 语法错误：缺少＆＃39;;＆＃39;在标识符＆＃39; aPolicy＆＃39;之前 Project6 c：\ users \ preston freeman \ source \ repos \ jave.cpp 40

错误 C2065 ＆＃39; aPolicy＆＃39;：未声明的标识符 Project6 c：\ users \ preston freeman \ source \ repos \ jave.cpp 40

错误 C2065 ＆＃39; aPolicy＆＃39;：未声明的标识符 Project6 c：\ users \ preston freeman \ source \ repos \ jave.cpp 44

错误 C2065 ＆＃39; aPolicy＆＃39;：未声明的标识符 Project6 c：\ users \ preston freeman \ source \ repos \ jave.cpp 45

如何解决这些错误？谢谢你的时间？

Answer 1

代码中有很多拼写错误，但主要问题是没有已知的从fstream到ofstream的转换，所以这里是正确的代码版本：

#include <iostream>
#include <fstream>
using namespace std;
class InsurancePolicy
{
    friend ofstream&  operator<<(ofstream&, InsurancePolicy);
    friend istream& operator>>(istream&, InsurancePolicy&);
private:
    int policyNum;
    string lastName;
    int value;
    int premium;
};
ofstream& operator<<(ofstream& out, InsurancePolicy pol)
{
    out << pol.policyNum << " " << pol.lastName << " " << pol.value << " " << pol.premium << endl;
    return out;
}
istream& operator>>(istream& in, InsurancePolicy& pol)
{
    in >> pol.policyNum >> pol.lastName >> pol.value >> pol.premium;
    return in;
}
int main() {
    ofstream outFile;
    outFile.open("Policy.txt");
    InsurancePolicy aPolicy[10];
    for (int count = 0; count < 10; ++count)
    {
        printf("Enter the policy number, the holder's last name, the value, and the premium.");
        cin >> aPolicy[count];
        outFile << aPolicy[count]<<std::endl;
    }
    return 0;

}

使用fstream的程序不会卷曲

1 个答案: