如何将#include <iostream> 添加到项目中？

Question

我刚开始学习 C++，我试图用 Visual Studio 2017 创建一个简单的代码。

#include "stdafx.h"
#include <iostream>
using namespace std;

int main()
{
int x;
std::cout >> "Enter Age";
std::cin >> x;

    if (x >= 18) {
        std::cout << "You are an adult." << endl;
    }
    else {
        std::cout << "You are a child." << endl;
    }

    return 0;
}

但我认为我遇到了很多错误，例如 iostream 不存在 因为我没有在头文件中看到它或 iostream.h 我尝试创建一个新的头文件并简单地键入 #include <iostream> 但这似乎不起作用。这是我的错误。

 1>c:\users\munta\onedrive\documents\visual studio 
 2017\projects\consoleapplication3\consoleapplication3\source.cpp(8): error 
 C2784: 'std::basic_istream<char,_Traits> &std::operator >>
 (std::basic_istream<char,_Traits> &,signed char &)': could not deduce 
 template argument for 'std::basic_istream<char,_Traits> &' from 
 'std::ostream'
 1>c:\program files (x86)\microsoft visual 
 studio17\community\vc\tools\msvc.10.25017\include\istream(1068): 
 note: see declaration of 'std::operator >>'
 1>c:\users\munta\onedrive\documents\visual studio 
 2017\projects\consoleapplication3\consoleapplication3\source.cpp(8): error 
 C2784: 'std::basic_istream<char,_Traits> &std::operator >>
 (std::basic_istream<char,_Traits> &,signed char *)': could not deduce 
 template argument for 'std::basic_istream<char,_Traits> &' from 
 'std::ostream'
 1>c:\program files (x86)\microsoft visual 
 studio17\community\vc\tools\msvc.10.25017\include\istream(1061): 
 note: see declaration of 'std::operator >>'
 1>c:\users\munta\onedrive\documents\visual studio 
 2017\projects\consoleapplication3\consoleapplication3\source.cpp(8): error 
 C2784: 'std::basic_istream<_Elem,_Traits> &std::operator >>
 (std::basic_istream<_Elem,_Traits> &,_Elem &)': could not deduce template 
 argument for 'std::basic_istream<_Elem,_Traits> &' from 'std::ostream'
 1>c:\program files (x86)\microsoft visual 
 studio17\community\vc\tools\msvc.10.25017\include\istream(1036): 
 note: see declaration of 'std::operator >>'
 1>c:\users\munta\onedrive\documents\visual studio 
 2017\projects\consoleapplication3\consoleapplication3\source.cpp(8): error 
 C2784: 'std::basic_istream<_Elem,_Traits> &std::operator >>
 (std::basic_istream<_Elem,_Traits> &,_Elem *)': could not deduce template 
 argument for 'std::basic_istream<_Elem,_Traits> &' from 'std::ostream'
 1>c:\program files (x86)\microsoft visual 
 studio17\community\vc\tools\msvc.10.25017\include\istream(995): note: 
 see declaration of 'std::operator >>'
 1>c:\users\munta\onedrive\documents\visual studio 
 2017\projects\consoleapplication3\consoleapplication3\source.cpp(8): error 
 C2676: binary '>>': 'std::ostream' does not define this operator or a 
 conversion to a type acceptable to the predefined operator
 1>Done building project "ConsoleApplication3.vcxproj" -- FAILED.

感谢您的帮助。

Answer 1

检查这个：std::cout >> "Enter Age";。我想应该是 std::cout << "Enter Age";。

顺便说一句，与问题无关，因为你正在写 std::cout 和 std::cin 那么如果你保持与 std::endl 而不是 [=15= 的一致性会更好].

Answer 2

问题在第 8 行。应该是：

std::cout << "Enter Age";

如何将#include <iostream> 添加到项目中？

How to add #include <iostream> to project?

c++

visual-studio

iostream