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

int main() {
  vector<int> tbl(10);  // creates length 10 vector of int
  tbl[5] = 7;           // stores 7 in slot #5
  cout << tbl[5];       // prints 7
  tbl[10] = 4;          // illegal, but not checked!!!
  cout << tbl.at(5);    // prints 7
  tbl.at(10) = 4;       // illegal and throws an exception
  tbl.push_back(4);     // creates tbl[10] and stores 4
  cout << tbl.at(10);   // prints 4
}