C++ 我的基本计算器应用程序中的一个变量是'；行不通 #包括 使用名称空间std； int main（） { cout>用户名； 库特数； cout>数字2； 双和； 总和=数字一+数字二； cout

在这一行：

#include <iostream>
using namespace std;
int main()
{
cout << "Hello user, please enter your name: ";
string userName;
cin >> userName;
cout << "Hello " + userName + ", welcome to the addition calculator.\n Please keep in mind that this calculator only supports two numbers.";

cout << "Please enter a number for the process for addition: ";
double numberOne;
cin >> numberOne;
cout << "Please enter a second number for the process for addition: ";
double numberTwo;
cin >> numberTwo;
double sum;
sum = numberOne + numberTwo;
cout << userName + ", thank you for using the addition calculator, the sum of your answer is " + sum;
return 0; 
}

或者像这样使用

std:：to_string

：

cout << userName 
     << ", thank you for using the addition calculator, the sum of your answer is " 
     << sum;
  // ^^^^^^   chaining is fine

---

cout
cin>>userName；
确保只询问名字，否则如果有人在名字和姓氏之间键入空格，那么接下来询问的double中会有不好的数据。我认为将字符串和变量链接在一起会更有效，而且，你说我可以在字符串上加一个double是什么意思，这是一个separate变量对吗？也谢谢你的回答，我很感激。但是类型不匹配，或者更确切地说，没有可以添加双精度和字符串的
+
（至少如果你想进行串联）。
cout << userName 
     << ", thank you for using the addition calculator, the sum of your answer is " 
     << sum;
  // ^^^^^^   chaining is fine

cout << userName 
      + ", thank you for using the addition calculator, the sum of your answer is " 
      + std::to_string(sum);
    //  ^^^^^^^^^^^^^^^^^^^   converting to a string and concatenating is fine