compare string c++

// 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; 
} 

// comparing apples with apples
#include <iostream>
#include <string>

int main ()
{
  std::string str1 ("green apple");
  std::string str2 ("red apple");

  if (str1.compare(str2) != 0)
    std::cout << str1 << " is not " << str2 << '\n';

  if (str1.compare(6,5,"apple") == 0)
    std::cout << "still, " << str1 << " is an apple\n";

  if (str2.compare(str2.size()-5,5,"apple") == 0)
    std::cout << "and " << str2 << " is also an apple\n";

  if (str1.compare(6,5,str2,4,5) == 0)
    std::cout << "therefore, both are apples\n";

  return 0;
}

std::ostringstream strs;
strs << dbl;
std::string str = strs.str();

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; 
}