String

#include <iostream>
using namespace std;

bool palin(string word){
        string rw("");

        //sol #1
        for (int x=0; x<word.size();x++)
        {
                rw = word[x] + rw; // ex: home= h, oh, moh, emoh
        }

        //sol #2
        /*
        for (int x=word.size()-1; x>=0 ;x--)
        {
                rw = rw + word[x]; // ex: home= e, em, emo, emoh
        }
        */

        return (rw==word);
        //if (rw==word)
        //      return true;
        //return false;
}

int main(){
        string w;
        cin >> w;
        if (palin(w))
        {
                cout<<w<< " is a palindrome"<<endl;
        }
        else
        {
                cout<<w<< " is NOT a palindrome"<<endl;
        }
        return 0;
}

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

int main(){
        string s("hello world");
        cout<<s.find("l")<<endl; //2
        cout<<s.rfind("l")<<endl; //9
        cout <<s.substr(6,3)<<endl; //wor
        if (s.find("xx") == string::npos) //true
        {
                cout<< "not found"<<endl;
        }
        cout<<s[9]<<endl; //no error
        cout<<s.at(9)<<endl;//runtime bounds checking error occurs
        cout<<s<<endl;
        return 0;
}

#include <iostream>
using namespace std;

//this program will replace a substring in a user input string
//this code works even when the new string has the old string in it

int main()
{
        string s;
        string ow;
        string nw;
        cout << "Enter a sentence: ";
        getline(cin, s);
        cout << "Enter a word to delete: ";
        getline(cin, ow);
        cout << "Enter another word which replaces the deleted word: ";
        getline(cin, nw);
        size_t pos(0);

        while ( (pos = s.find(ow, pos)) != string::npos )
        {
           s.replace( pos, ow.size(), nw);
           pos = pos + nw.size();
        }

        cout << s << endl;

        return 0;
}