Question

我是一名新手学生，在接受cse 100帮助时，理解这个主题表示赞赏。它编译得很好，但是在运行时它只提示用户一次，经过几次更改，老师建议现在程序没有编译。它给了我以下错误。

main.cpp|30|error: no match for 'operator*' (operand types are 'const double' and 'std::string {aka std::basic_string<char>}')|

main.cpp|33|error: no match for 'operator*' (operand types are 'const double' and 'std::string {aka std::basic_string<char>}')| 

main.cpp|36|error: no match for 'operator+' (operand types are 'std::string {aka std::basic_string<char>}' and 'double')|

尝试过的代码：

#include <iostream>

using namespace std;

int main()
{
    const double adultTicket = 9.50; //declared const double with value of
    //$9.50price per adult ticket.
    const double childTicket = 6.50; //declared const double with value
    //of $6.050 per child ticket.

    cout << "Please enter movie name \n"; //User prompt to enter movie name.
    string movName;
    getline(cin,movName); //Declared variable told name entered by user.

    cout << "Please enter number of Adult tickets sold \n"; //User prompt to
    //enter amounnt of adult tickets sold.
    string adultTicketsSold;
    getline(cin, adultTicketsSold); //Declared variable that holds number of
    //adult tickets sold.

    cout << "Please enter number of children tickets sold \n"; //User prompt
    //to enter number of children tickets sold.
    string childTicketsSold;
    getline(cin,childTicketsSold); // Declared variable to hold number of
    //child tickets sold.

    string grossAdult;
    grossAdult = adultTicket*adultTicketsSold;

    double grossChild;
    grossChild = childTicket*childTicketsSold;

    double grossBox;
    grossBox = grossAdult+grossChild;

    double distributorTake;
    distributorTake = grossBox*0.80;

    double netBox;
    netBox = grossBox*0.20;

    cout << "Revenue Report" <<endl;
    cout << "Movie name:" << movName <<endl;
    cout << "Adult Tickets Sold:" << adultTicketsSold <<endl;
    cout << "Child Tickets Sold:" << childTicketsSold <<endl;
    cout << "Gross Box Office Profit: $" << grossBox <<endl;
    cout << "Amount Paid to Distributor: $" << distributorTake <<endl;
    cout << "Net Box Office Profit: $" << netBox <<endl;
    return 0;
}

Answer 1

问题在于这些问题，您尝试将std::string乘以double，而不是将两个double相乘。

grossAdult = adultTicket*adultTicketsSold;

您可以使用std::stod

将std::string转换为double

grossAdult = adultTicket * std::stod(adultTicketsSold);

或者如果您愿意，您可以接受double作为输入，而不是进行转换

cout << "Please enter number of Adult tickets sold \n";
double adultTicketsSold;
cin >> adultTicketsSold;

编译器给我一个错误：不匹配＆＃39;运算符*＆＃39;

1 个答案: