Define a class String use overloaded operator to compare two strings

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Pre-requisite: Operator Overloading in C++
Given two strings, how to check if the two strings are equal or not, using Operator Overloading.

Examples: 

Input: ABCD, XYZ
Output: ABCD is not equal to XYZ
        ABCD is greater than XYZ

Input: Geeks, Geeks
Output: Geeks is equal to Geeks

Approach: Using binary operator overloading. 

• Declare a class with a string variable and operator function ‘==’, ‘<=’ and ‘>=’ that accepts an instance of the class and compares it’s variable with the string variable of the current instance.
• Create two instances of the class and initialize their class variables with the two input strings respectively.
• Now, use the overloaded operator(==, <= and >=) function to compare the class variable of the two instances.

Below is the implementation of the above approach: 

C++

#include <cstring>

#include <iostream>

#include <string.h>

using namespace std;

class CompareString {

public:

    char str[25];

    CompareString(char str1[])

    {

        strcpy(this->str, str1);

    }

    int operator==(CompareString s2)

    {

        if (strcmp(str, s2.str) == 0)

            return 1;

        else

            return 0;

    }

    int operator<=(CompareString s3)

    {

        if (strlen(str) <= strlen(s3.str))

            return 1;

        else

            return 0;

    }

    int operator>=(CompareString s3)

    {

        if (strlen(str) >= strlen(s3.str))

            return 1;

        else

            return 0;

    }

};

void compare(CompareString s1, CompareString s2)

{

    if (s1 == s2)

        cout << s1.str << " is equal to "

             << s2.str << endl;

    else {

        cout << s1.str << " is not equal to "

             << s2.str << endl;

        if (s1 >= s2)

            cout << s1.str << " is greater than "

                 << s2.str << endl;

        else

            cout << s2.str << " is greater than "

                 << s1.str << endl;

    }

}

void testcase1()

{

    char str1[] = "Geeks";

    char str2[] = "ForGeeks";

    CompareString s1(str1);

    CompareString s2(str2);

    cout << "Comparing \"" << s1.str << "\" and \""

         << s2.str << "\"" << endl;

    compare(s1, s2);

}

void testcase2()

{

    char str1[] = "Geeks";

    char str2[] = "Geeks";

    CompareString s1(str1);

    CompareString s2(str2);

    cout << "\n\nComparing \"" << s1.str << "\" and \""

         << s2.str << "\"" << endl;

    compare(s1, s2);

}

int main()

{

    testcase1();

    testcase2();

    return 0;

}

Output:

Comparing "Geeks" and "ForGeeks"
Geeks is not equal to ForGeeks
ForGeeks is greater than Geeks


Comparing "Geeks" and "Geeks"
Geeks is equal to Geeks