C/C++中char[]和string的连接/合并

#include <iostream>
using namespace std;

int main()
{
  const char *str = "hello ";
  const char *str2 = "world";
  const size_t len = strlen(str)+strlen(str2);
  char *n_str = new char[len+1];
  strcpy(n_str,str);
  strcat(n_str,str2);
  cout<<n_str<<endl;
  delete [] n_str;
  return 0;
}

 二：C++ string类型字符串 

#include <iostream>
#include <string>
using namespace std;

int main()
{
  const string str="hello ";
  const string str2="world";
  string n_str;
  n_str = str;
  n_str +=str2;
  cout<<n_str<<endl;
  return 0;
}