c++ 字符串拷贝以及合并

#include<iostream>
#include<string>
using namespace std;
class stringfun
{
    char name[];
    public:
       void concatString(char a[],char b[])
       {
          strcat(a," ");
          strcat(a,b);
          strcpy(name,a);
       }
       void display()
       {
          cout<<"\nName : "<<name;
       }
};
int main()
{
    char str1[],str2[];

    stringfun sf;

    cout<<"Enter your name:";
    gets(str1);
    cout<<"Enter sir name:";
    gets(str2);
    sf.concatString(str1,str2);
    sf.display();
    return ;
}