C++错误C2040？

Question

错误信息:

这是什么意思？

我该如何解决？

错误C2040:'==':'int'的间接级别与'const char [2]'不同

码:

#include <iostream>
#include <cmath>
using namespace std;

int round(double number);
//Assumes number >=0.
//Returns number rounded to the nearest integer.

int main()
{
    double doubleValue;
    char ans;

    do
    {
        cout << "Enter a double value: ";
        cin >> doubleValue;
        cout << "Rounded that number is " <<round(doubleValue)<< endl;
        cout << "Again? (y/n): ";
        cin >> ans;

    }
    //Here is the line generating the problem, while(...);

    while (ans == 'y' || ans == "Y");

    cout << "End of testing.\n";

    return 0;
}

//Uses cmath
int round(double number)
{
    return static_cast<int>(floor(number + 0.5));
}

Answer 1

你需要单引号char文字.你为第一个而不是第二个正确地做了这个:

while (ans == 'y' || ans == "Y");

这应该是:

while (ans == 'y' || ans == 'Y');

双引号用于string(const char[])文字.