问题
I know it is a common issue, but looking for references and other material I don't find a clear answer to this question.
Consider the following code:
#include <string>
// ...
// in a method
std::string a = "Hello ";
std::string b = "World";
std::string c = a + b;
The compiler tells me it cannot find an overloaded operator for char[dim].
Does it mean that in the string there is not a + operator?
But in several examples there is a situation like this one. If this is not the correct way to concat more strings, what is the best way?
回答1:
Your code, as written, works. You’re probably trying to achieve something unrelated, but similar:
std::string c = "hello" + "world";
This doesn’t work because for C++ this seems like you’re trying to add two char pointers. Instead, you need to convert at least one of the char* literals to a std::string. Either you can do what you’ve already posted in the question (as I said, this code will work) or you do the following:
std::string c = std::string("hello") + "world";
回答2:
std::string a = "Hello ";
a += "World";
回答3:
I would do this:
std::string a("Hello ");
std::string b("World");
std::string c = a + b;
Which compiles in VS2008.
回答4:
std::string a = "Hello ";
std::string b = "World ";
std::string c = a;
c.append(b);
来源：https://stackoverflow.com/questions/4304662/concatenating-strings-doesnt-work-as-expected