Why I cannot cout
string
like this:
string text ;
text = WordList[i].substr(0,20) ;
cout << "String is : " << text << endl ;
When I do this, I get the following error:
Error 2 error C2679: binary '<<': no operator found which takes a right-hand operand of type 'std::string' (or there is no acceptable conversion) c:\users\mollasadra\documents\visual studio 2008\projects\barnamec\barnamec\barnamec.cpp 67 barnamec**
It is amazing, that even this is not working:
string text ;
text = "hello" ;
cout << "String is : " << text << endl ;
You need to include
#include <string>
#include <iostream>
You need to reference the cout's namespace std
somehow. For instance, insert
using std::cout;
using std::endl;
on top of your function definition, or the file.
There are several problems with your code:
WordList
is not defined anywhere. You should define it before you use it.#include <string>
before you can use the string class and iostream before you use cout
or endl
.string
, cout
and endl
live in the std
namespace, so you can not access them without prefixing them with std::
unless you use the using
directive to bring them into scope first. Above answers are good but If you do not want to add string include, you can use the following
ostream& operator<<(ostream& os, string& msg)
{
os<<msg.c_str();
return os;
}
Use c_str() to convert the std::string to const char *.
cout << "String is : " << text.c_str() << endl ;
You do not have to reference std::cout
or std::endl
explicitly.
They are both included in the namespace std
. using namespace std
instead of using scope resolution operator ::
every time makes is easier and cleaner.
#include<iostream>
#include<string>
using namespace std;
If you are using linux system then you need to add
using namespace std;
Below headers
If windows then make sure you put headers correctly #include<iostream.h>
#include<string.h>
Refer this it work perfectly.
#include <iostream>
#include <string>
int main ()
{
std::string str="We think in generalities, but we live in details.";
// (quoting Alfred N. Whitehead)
std::string str2 = str.substr (3,5); // "think"
std::size_t pos = str.find("live"); // position of "live" in str
std::string str3 = str.substr (pos);
// get from "live" to the end
std::cout << str2 << ' ' << str3 << '\n';
return 0;
}
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.