string comparison in c++

int compare (const string& str) const;
// CPP code to implement relational 
// operators on string objects 
#include <iostream> 
using namespace std; 
  
void relationalOperation(string s1, string s2) 
{ 
  
    if (s1 != s2) 
        cout << s1 << " is not equal to "
             << s2 << endl; 
    if (s1 > s2) 
        cout << s1 << " is greater than "
             << s2 << endl; 
    else
        cout << s2 << " is greater than "
             << s1 << endl; 
} 
  
// Main function 
int main() 
{ 
    string s1("Geeks"); 
    string s2("forGeeks"); 
    relationalOperation(s1, s2); 
    return 0; 
} 
// CPP code perform relational 
// operation using compare function 
#include <iostream> 
  
using namespace std; 
  
void compareFunction(string s1, string s2) 
{ 
    // comparing both using inbuilt function 
    int x = s1.compare(s2); 
  
    if (x != 0) 
        cout << s1 << " is not equal to "
             << s2 << endl; 
    if (x > 0) 
        cout << s1 << " is greater than "
             << s2 << endl; 
    else
        cout << s2 << " is greater than "
             << s1 << endl; 
} 
  
// Main function 
int main() 
{ 
    string s1("Geeks"); 
    string s2("forGeeks"); 
    compareFunction(s1, s2); 
    return 0; 
}