Vector class in C++ (Part of STL)

 //Use of vector template in cpp

#include<iostream>

#include<vector>

using namespace std;

int main()

{

    vector<int> v;

    cout<<v.size();//will display size of vector

    v.push_back(10);//to add value to vector

    v.push_back(20);

    cout<<v.size();//will display size after adding values

    cout<<endl<<"values of vector"<<endl;

    cout<<v[0];//to display first value

    cout<<v[1];

     cout<<endl<<"values of vector through iterator";

   vector<int>::iterator it = v.begin();

   while( it != v.end()) {

      cout <<endl<<"value of it = " << *it;

      it++;

   }//end of while

   v.push_back(30);

   v.push_back(40);

   cout<<endl<<"now the size of vector is "<<v.size();

    cout<<endl<<"Now values of vector are:";

    for(int i=0;i<v.size();i++)

        cout<<endl<<v[i];

/*so the conclusion of vector is, it is a class

that can be used to store values with in-built feature to 

expand the size of vector itself.So it is implementing the 

data structures who can expand at run time.

*/

}//end of main

OUTPUT :

02

values of vector

1020

values of vector through iterator

value of it = 10

value of it = 20

now the size of vector is 4

Now values of vector are:

10

20

30

40