Question

我在程序中遇到同样的错误，非常感谢任何帮助。

错误1错误C2784：'std :: basic_istream＆lt; _Elem，_Traits＆gt;   ＆安培;的std ::函数getline（标准:: basic_istream＆LT; _Elem，_Traits＆GT;   ＆安培;，的std :: basic_string的＆LT; _Elem，_Traits，_Alloc＆GT; ＆amp;）'：无法演绎   'std :: basic_string＆lt; _Elem，_Traits，_Alloc＆gt;的模板参数＆安培;”从   'char'c：\ Users \ esmier \ Documents \ Visual Studio 2008 \ Projects \ Chapter 4   实验室\第4章lab \ source.cpp 40第4章实验室

错误2错误C2780：'std :: basic_istream＆lt; _Elem，_Traits＆gt;   ＆安培;的std ::函数getline（标准:: basic_istream＆LT; _Elem，_Traits＆GT;   ＆安培;，的std :: basic_string的＆LT; _Elem，_Traits，_Alloc＆GT; ＆amp;，const _Elem）'：预计3   参数 - 2提供了c：\ Users \ esmier \ Documents \ Visual Studio   2008 \ Projects \ Chapter 4 lab \ Chapter 4 lab \ source.cpp 40第4章实验室

在作为案例b评论的部分中也会出现错误

#include <iostream>
#include<sstream>
int main()
{
double hours;
double Package_A_price=9.95, Package_A_hours=10, Package_A_additional=2.00,Package_A_total;
double Package_B_price=14.95, Package_B_hours=20, Package_B_additional=1.00,Package_B_total;
double Package_C_price=19.95;
char package_choice, additional_hours[3];

//table output

cout<<"Please choose your package below";

cout<<"Package A:\t"<<"For $9.95 per month 10 hours of service are provided.\n";
cout<<"\t\tAdditional hours are $2.00 per hour\n\n";

cout<<"Package B:\t"<<"For $14.95 per month 20 hours of service are provided.\n";
cout<<"\t\tAdditional hours are $1.00 per hour\n\n";

cout<<"Package A:\t"<<"For $19.95 per month unlimited access is provided.\n\n\n";

cout<<"What is your package letter?\n";
cin>>package_choice;
while (package_choice!='A'||'a'||'B'||'b'||'C'||'c')
{
    cout<<"You entered an incorrect option.\n";
    cout<<"please reenter your choice.\n\n";
}
switch (package_choice)
{
//package A choice
case 'A||a':
    cout<<"Did you have any additional hours?\n";
    getline(cin, additional_hours);
    if (additional_hours == 'yes')
    {
        cout<<"How many hours did you have?\n";
        cin>>hours;
        while (hours >744)
        {
            cout<<"You can not have over 744 hours per month!\n";
            cout<<"Time is a linear constant, Please renter your amount.\n";
        }
        Package_A_total=9.95+(2.00*hours);
        cout<<"Your Total for Package A is $"<<Package_A_total;
        break;
    }
//package B choice
case 'B||b':
    cout<<"Did you have any additional hours?\n";
    getline(cin, additional_hours);
    if (additional_hours == 'yes')
    {
        cout<<"How many hours did you have?\n";
        cin>>hours;
        while (hours >744)
        {
            cout<<"You can not have over 744 hours per month!\n";
            cout<<"Time is a linear constant, Please renter your amount.\n";
        }
        Package_B_total=14.95+(1.00*hours);
        cout<<"Your Total for Package B is $"<<Package_B_total;
        break;
    }
//package C choice
case 'C||c':
    cout<<"Your Total for Package C is $"<<Package_B_price;
    break;

default: cout<<"You did not Enter A B or C.\n";
         cout<<"Please reenter your choice.";
}



system ("pause");
    return 0;

}

Answer 1

additional_hours被声明为~~一个字符~~一个包含3个字符的数组。这种形式的getline期望你使用std :: string（另一种用于C风格char*的形式是cin的成员函数。）

还有很多其他错误，显然你不知道 char 意味着一个字符：

case 'A||a':
if (additional_hours == 'yes')

那些使用多字节字符常量。基本上它并不意味着你所期望的（它是用ASCII字符编码的单个数字或类似的东西）。

while (package_choice!='A','a','B','b','C','c')

同样，这不是你如何比较多个条件，你需要将它们与逻辑和和（和＆amp;＆amp;和||）结合起来。实际上，它使用逗号运算符，这意味着计算所有操作数并使用最后一个（'c'）作为结果。

此外，<cctype>中的tolower或toupper功能可能会对您有所帮助。

启用编译器警告（-Wall with GCC）可能会显示所有这些错误：[警告]多字符字符常量，[警告]逗号的左侧操作数无效，[警告]案例标签值超过最大值对于类型，由于数据类型的范围有限，[Warning]比较始终为false。

编辑：既然您已将additional_hours声明为字符数组，您应该知道3个字符不足以存储字符串“yes”，因为空终止符没有空间。你最好使用std :: string类。

Answer 2

我看到你的while循环没有重置package_choice的一个漏洞：

while (package_choice!='A','a','B','b','C','c'){       
         cout<<"You entered an incorrect option.\n";        
         cout<<"please reenter your choice.\n\n";
}

你需要cin＆gt;＆gt;再次选择包裹。

Answer 3

它似乎不喜欢你传入getline的内容。尝试将additional_hours声明为std::string。

Answer 4

使用std::cout或std::cin或std::cin.getline(..)代替您正在使用的内容。

使用std::cin.get()代替system("pause")来固定屏幕

Answer 5

试试这个：

cin.getline(additional_hour, 3)

c ++错误，“无法推断出'std ...'的参数

5 个答案: