Vector and Iterator in C++

PROGRAM:

#include <iostream>
#include <vector>

using namespace std;

int main(int argc, char *argv[])
{
        vector<int> myarr;

        cout << "\nSize : " << myarr.size() << endl;

        //put data at vector
        myarr.push_back(5);
        myarr.push_back(10);
        myarr.push_back(15);
        myarr.push_back(20);
        myarr.push_back(25);

        cout << "\nSize : " << myarr.size() << endl;
        for (int i = 0; i < myarr.size(); i++)
                cout << "\tArray values " << myarr[i] << endl;

        //delete first value
        myarr.erase(myarr.begin());

        cout << "\nSize : " << myarr.size() << endl;
        for (int i = 0; i < myarr.size(); i++)
                cout << "\tArray values " << myarr[i] << endl;

        //delete last value
        myarr.erase(myarr.end()-1);

        cout << "\nSize : " << myarr.size() << endl;
        for (int i = 0; i < myarr.size(); i++)
                cout << "\tArray values " << myarr[i] << endl;

        //insert at position
        myarr.insert(myarr.begin()+2, 100);

        cout << "\nSize : " << myarr.size() << endl;
        for (int i = 0; i < myarr.size(); i++)
                cout << "\tArray values " << myarr[i] << endl;

        //delete middle value
        myarr.erase(myarr.begin()+1);

        cout << "\nSize : " << myarr.size() << endl;
        for (int i = 0; i < myarr.size(); i++)
                cout << "\tArray values " << myarr[i] << endl;

        return 0;
}

OUTPUT:

Size : 0

Size : 5
        Array values 5
        Array values 10
        Array values 15
        Array values 20
        Array values 25

Size : 4
        Array values 10
        Array values 15
        Array values 20
        Array values 25

Size : 3
        Array values 10
        Array values 15
        Array values 20

Size : 4
        Array values 10
        Array values 15
        Array values 100
        Array values 20

Size : 3
        Array values 10
        Array values 100
        Array values 20

Addition program using class and object in C++

PROGRAM : 

#include <iostream>
#include <string.h>
using namespace std;
 
class addition
{
    private:
        int var1, var2, result;
    public:
        void getValue();
        int addOperation();
};
 
void addition :: getValue()
{
        cout << "Enter the first value : " << "\n";
        cin >> var1;
        cout << "Enter the second value : " << "\n";
        cin >> var2;
}
 
int addition :: addOperation()
{
        result = var1 + var2;
        return result;
}
 
int main(int argc, char *argv[])
{
        addition obj1;
        int output = 0;
        obj1.getValue();
        output = obj1.addOperation();
        cout << "Result : " << output << endl;
        return 0;
}

OUTPUT : 
Enter the first value : 
25
Enter the second value : 
30

Result : 55