C ++ Hello World Tutorial错误

Question

I'm learning C++ by following examples in a book and after typing this out and double checking I keep getting error messages. I cant figure out what is wrong. I'm using Visual C++ 2010 if it matters.

#include <iostream>
using namespace std;

int main()
{
// Prompt the user for data 
cout << "Please enter two words:" << endl;

//Read in the values
string b, c;
cin >> b >> c;

// Give feedback
cout << "I understood: "
     << b << ", and "
     << c << endl;

// NOw, lets's read a whole line of text as a single entity
cout << "Now, type in a whole line of text, "
     << "with as many blanks as you want:"
     << endl;

//getline() is a function; we'll talk more about them in Part3 
string wholeLine;
getline( cin, wholeLine );

//In the cout statement below, remember that \"
// is an escape sequence!
cout << "I understood: \"" << wholeLine << "\"" << endl;

// And we're done! 
return 0;
}

There are four errors. The error codes are:

Error 1 error C2678: binary '>>' : no operator found which takes a left-hand operand of type 'std::istream' (or there is no acceptable conversion) i:\\helloworld.cpp 11

Error 2 error C2679: binary '<<' : no operator found which takes a right-hand operand of type 'std::string' (or there is no acceptable conversion) i:\\helloworld.cpp 15

Error 3 error C3861: 'getline': identifier not found i:\\helloworld.cpp 25

Error 4 error C2679: binary '<<' : no operator found which takes a right-hand operand of type 'std::string' (or there is no acceptable conversion) i:\\helloworld.cpp 29

Answer 1

缺少#include <string>表示string 。

Answer 2

As Wesley already said, ensure you have the library included.

Also, be very careful when using getline() and cin in the same program. One can affect the other and you can get unexpected results. To be safe, I've found that it is useful to use cin.ignore() after using a cin and before using a getline. Cheers!