How to copy a string of std::string type in C++?

Question

I used the strcpy() function and it only works if I use C-string arrays like:

char a[6] = "text"; char b[6] = "image"; strcpy(a,b); 

but whenever I use

string a = "text"; string b = "image"; strcpy(a,b); 

I get this error:

functions.cpp: no matching function for call to strcpy(std::string&, std::string&)

How to copy 2 strings of string data type in C++?

Answer 1

You shouldn't use strcpy() to copy a std::string, only use it for C-Style strings.

If you want to copy a to b then just use the = operator.

string a = "text"; string b = "image"; b = a; 

Answer 2

strcpy is only for C strings. For std::string you copy it like any C++ object.

std::string a = "text"; std::string b = a; // copy a into b 

If you want to concatenate strings you can use the + operator:

std::string a = "text"; std::string b = "image"; a = a + b; // or a += b; 

You can even do many at once:

std::string c = a + " " + b + "hello"; 

Although "hello" + " world" doesn't work as you might expect. You need an explicit std::string to be in there: std::string("Hello") + "world"