String Implementation

/* Implementing String class
*/

#include <iostream>
#include <cstdlib>
#include <cstring>
#include <cstdio>

using namespace std;

class String{
    char *str;
    int size;
    public:
        String(const char* = "");
        ~String();
        int length();
        bool operator >(String&);
        bool operator <(String&);
        bool operator ==(String&);
        friend istream& operator >>(istream&, String&);
        friend ostream& operator <<(ostream&, String&);
};

inline String::String(const char *str){
    String::str = new char[strlen(str) + 1];
    strcpy(String::str, str);
    size = strlen(str);
}

inline String::~String(){
    delete[] str;
    str = NULL;
}

inline int String::length(){
    return size;
}

inline bool String::operator >(String &obj){
    return strcmp(str, obj.str) > 0;
}

inline bool String::operator <(String &obj){
    return strcmp(str, obj.str) < 0;
}

inline bool String::operator ==(String &obj){
    return strcmp(str, obj.str) == 0;
}

istream& operator >>(istream &in, String &obj){
    /* Try to do this in the constructor */
    char temp[1024];
    gets(temp);
    delete[] obj.str;
    obj.str = new char[strlen(temp) + 1];
    strcpy(obj.str, temp);
    return in;
}

ostream& operator <<(ostream &out, String &obj){
    out << obj.str;
    return out;
}

int main() {
    system("cls");
    cout << "Enter the first string: ";
    String str1;
    cin >> str1;
    cout << "Enter the second string: ";
    String str2;
    cin >> str2;
    if(str1 > str2){
        cout << str1 << " is greater than " << str2;
    }
    else if(str1 < str2){
        cout << str1 << " is lesser than " << str2;
    }
    else {
        cout << str1 << " is equal to " << str2;
    }
    cin.get();
    return 0;
}