c++ - 无法编译C++程序

Question

这是代码......

#include <iostream>

int main()
{
    cout << "WELCOME TO C++ PROGRAMMING";
    return 0;
}

当我进入终端并传递命令时..

g++ hello.cpp

它显示...

hello.cpp: In function ‘int main()’:
hello.cpp:4:2: error: ‘cout’ was not declared in this scope
  cout << "WELCOME TO C++ PROGRAMMING";
  ^
hello.cpp:4:2: note: suggested alternative:
In file included from hello.cpp:1:0:
/usr/include/c++/4.8/iostream:61:18: note:   ‘std::cout’
   extern ostream cout;  /// Linked to standard output

那这是什么原因呢？我该怎么办？

Answer 1

cout位于 std 命名空间中。

#include <iostream>

int main()
{
    std::cout << "Welcome";
    return 0;
}