string, char *, int data type conversion

string type to convert char * type, there are generally three methods:
1.c_str () method

string name="Qian";
char *str=(char*)name.c_str();
printf("%s\n",str);

2.data () method

string name="Qian";
char *str=(char*)name.data();
printf("%s\n",str);

3.copy () method

string name="James";
char str[10];
name.copy (STR, . 5 , 0 ); // . 5 representative of the number of characters copied initial position, 0 replicated 
STR [ . 6 ] = ' \ 0 ' ; // be sure to add its own end of the string 
the printf ( " S% \ n- " , STR);

string type to int type

string str="1";
stringstream ss;
ss<<str;
ss>>a;

I.e., use as an intermediate is converted stringstream ss amount

int converted into type string type described above also