C++ 字符串连接运算符<

Question

I have realised my mistake. I was trying to concatenate two strings.

I have just started to learn C++. I have a problem about string concatenation. I don't have problem when I use:

cout << "Your name is"<<name;

But when I try to do it with a string:

string nametext;
nametext = "Your name is" << name;
cout << nametext;

I got an error. How can I concatenate two strings?

Answer 1

对于 C++ 中的字符串连接，您应该使用+运算符。

nametext = "Your name is" + name;

Answer 2

First of all it is unclear what type name has. If it has the type std::string then instead of

string nametext;
nametext = "Your name is" << name;

you should write

std::string nametext = "Your name is " + name;

where operator + serves to concatenate strings.

If name is a character array then you may not use operator + for two character arrays (the string literal is also a character array), because character arrays in expressions are implicitly converted to pointers by the compiler. In this case you could write

std::string nametext( "Your name is " );
nametext.append( name );

or

std::string nametext( "Your name is " );
nametext += name;

Answer 3

nametext is an std::string but these do not have the stream insertion operator ( << ) like output streams do.

To concatenate strings you can use the append member function (or its equivalent, += , which works in the exact same way) or the + operator , which creates a new string as a result of concatenating the previous two.

Answer 4

You can combine strings using stream string like that:

#include <iostream>
#include <sstream>
using namespace std;
int main()
{
    string name = "Bill";
    stringstream ss;
    ss << "Your name is: " << name;
    string info = ss.str();
    cout << info << endl;
    return 0;
}

Answer 5

nametext = "Your name is" + name;

我认为这应该做