Question

我正在构建一个用户可以选择的简单菜单。出于某种原因

else if (letterSelect == "C" || letterSelect = "c")

||出现错误。另一个||工作得很好。错误是：没有运算符“||”匹配这些操作数。操作数类型是;布尔||的std :: string

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

int main()
{


cout << "********* General Purpose Calculator Program ***************\n"
    << "Please Select an Option by inputting its associated letter\n"
    << "A)  Determine Highest of Three Numbers\n"
    << "B) Reverse a Number\n"
    << "C)Calculate Parking Garage Charges\n"
    << "D) Exit\n";

string letterSelect = " ";


cin >> letterSelect;

if (letterSelect == "A" || letterSelect == "a")

{

    //call program listed for A;

}

else if (letterSelect == "B" || letterSelect == "b")

{

    //call program listed for B;

}

else if (letterSelect == "C" || letterSelect = "c")

{

    //call program listed for C;

}

else (letterSelect == "D" || letterSelect == "d");


    cout << "Exiting...";


}

Answer 1

下面：

else if (letterSelect == "C" || letterSelect = "c")

您在第二部分条件中缺少=。它应该是letterSelect == "c"

Answer 2

只是一个错字。 '||'的右侧在您的代码中是赋值（=），而不是相等检查（==）。

Answer 3

代码行

letterSelect = "c"

是分配操作而不是比较。将其更改为

letterSelect == "c"

它应该有用。

快乐的编码。

||不工作在if else C ++

3 个答案: