#include <iostream>
#include <string>
using namespace std;

int main()
{
        //Constructors
    string str1("first string");     // initialization by a C string 
    string str2(str1);              // initialization from another string object
    string str3(5, '#');            //initialization by number of copies of character
    string str4(str1, 6, 6);        // initialization by part of another string, start from 6th index, take 6 characters (third parameter) 
    cout << str1 << "\t" << str2 << "\t" << str3 << "\t" << str4 << endl;
    
    char c = str4[1];               //get character by indexing 
    cout << c << endl;
    str4[1] = 'p';                  //change character by indexing
    cout << str4 << endl;
    
    string str5 = str4 + str4;             //overloaded + for concatenation
    string str6 = str2.append(str3);        //append function for concatenation
    cout << str5 << "\t" << str6 << endl;
    
    cout << str6.length() << endl;              //length function
    
    string str7 = str6.substr(3, 6);     //extract substring from string starting at index 3, 6 characters
    cout << str7 << endl;
    return 0;
}