连接也有这么几个法

#include<iostream>
using namespace std;
int main()
{int i=0,j=0;
char a[80],b[40];
cin>>a;
cin>>b;
cout<<endl;
while(a[i]!='\0')
i++;
while(b[j]!='\0')
{a[i]=b[j];
 i++;
 j++;
}
a[i]='\0';
cout<<a<<endl;
return 0;
}

#include<iostream>
using namespace std;
int main()
{int i=0,j=0;
char a[80],b[40];
cin>>a;
cin>>b;
cout<<endl;
strcat(a,b);
cout<<a<<endl;
return 0;
}

#include<iostream>
#include<string>
using namespace std;
int main()
{string a,b;
cin>>a;
cin>>b;
a=a+b;
cout<<a<<endl;
return 0;