How to convert string to char array in C++?

Ok, i am shocked that no one really gave a good answer, now my turn. There are two cases;

  1. A constant char array is good enough for you so you go with,

    const char *array = tmp.c_str();
    
  2. Or you need to modify the char array so constant is not ok, then just go with this

    char *array = &tmp[0];
    

Both of them are just assignment operations and most of the time that is just what you need, if you really need a new copy then follow other fellows answers.


Simplest way I can think of doing it is:

string temp = "cat";
char tab2[1024];
strcpy(tab2, temp.c_str());

For safety, you might prefer:

string temp = "cat";
char tab2[1024];
strncpy(tab2, temp.c_str(), sizeof(tab2));
tab2[sizeof(tab2) - 1] = 0;

or could be in this fashion:

string temp = "cat";
char * tab2 = new char [temp.length()+1];
strcpy (tab2, temp.c_str());

str.copy(cstr, str.length()+1); // since C++11
cstr[str.copy(cstr, str.length())] = '\0';  // before C++11
cstr[str.copy(cstr, sizeof(cstr)-1)] = '\0';  // before C++11 (safe)

It's a better practice to avoid C in C++, so std::string::copy should be the choice instead of strcpy.