我是C++的初学者,所以我只是在阅读文章和书籍时将一些东西搞乱了。但我花了20分钟时间重复阅读这些内容,我无法分辨出它有什么问题。编译器在减去std :: strings时出错
#include <iostream>
#include <string>
using namespace std;
int main()
{
cout << "Hello there, this is your personal simple calculator.";
cin.get();
cout << "Type in what you want to do. (Addition, Subtraction, Multiplication, Division)"<< endl;
string c;
getline (cin, c);
if (c == "Addition")
{
string a_1;
string a_2;
cout << "You chose addition. Press enter" << endl ;
cin.get();
cout << "Type in the first value: ";
getline(cin, a_1);
cout << "Type in the second value: ";
getline (cin, a_2);
cout << a_1 << " + " << a_2 << " = " << a_1 + a_2 << endl;
}
else
{
cout << "You spelled it wrong.";
return 0;
}
if (c == "Subtraction")
{
string s_1;
string s_2;
cout << "You chose subtraction. Press enter" << endl ;
cin.get();
cout << "Type in the first value: ";
getline (cin, s_1);
cout << "Type in the second value: ";
getline (cin, s_2);
cout << s_1 << " - " << s_2 << " = " << s_1 - s_2 << endl;
}
}
我得到这个作为唯一的错误
42 83 C:\ Users \用户杰森\桌面\课 - 头文件\ LH1.cpp [错误]敌不过在 '操作符 - ' 'first_argument - second_argument'
我不明白。加法符号起作用,除了减法运算以外的所有内容。 所以我用别的
cout << first_argument << " - " << second_argument << " = " << first_argument - second_argument << endl;
乱七八糟的东西,但周围是减法部分工作正常。我不明白。请帮助
请考虑一个更具描述性的标题。这个头衔可能适用于数千个问题。 – chris 2014-08-28 22:23:15
'std :: string'没有'operator-'。 – juanchopanza 2014-08-28 22:27:02
'std :: string'的'+'运算符是串联的。没有'operator-',我不知道你应该怎么做。 – Blastfurnace 2014-08-28 22:27:34