char*，const char*，string的相互转换

string s =”abc”;
const char* c_s = s.c_str();

const char* c_s =”abc”;
string s(c_s);

string s =”abc”;
char* c;
const int len = s.length();
c =newchar[len+1];
strcpy(c,s.c_str());

char* c =”abc”;
string s(c);

constchar* cpc =”abc”;
char* pc =newchar[100];//足够长
strcpy(pc,c);