How do I sum two strings

Question

Today I was trying to sum two strings in c ++ that was for a program that I was coding but I tried to sum the string in two ways and I could not find the correct way to sum them, the forms I used were:

1st form:
std :: string a = "Hello";
std :: string b = "world";
std :: string c = b + a;
cout << c << endl;

2nd form:
std :: string a = "Hello";
std :: string b = "world";
std :: stringstream ex;
ex << a << b;
cout << ex << endl;

But, both ways give the compiler an error. Can anyone tell me an alternative to sum two strings?

Please the alternative is not strcat

Answer 1

You can either use the append method provided for strings:

https://en.cppreference.com/w/cpp/string/basic_string/append

Or the + operator, since it is overloaded for this purpose (both + and += are overloaded, dependant on which one you plan to use):

https://en.cppreference.com/w/cpp/string/basic_string/operator%2B%3D

https://en.cppreference.com/w/cpp/string/basic_string/operator%2B