C++/Vector/vector front

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Demonstrating the STL vector front and erase operations.

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

int main()
{
  string s("abcdefghij");
  vector<char> vector1(s.begin(), s.end());
  cout << "Popping characters off the front produces: ";
  while (vector1.size() > 0) {
    cout << vector1.front();
    vector1.erase(vector1.begin());
  }
  cout << endl;
  return 0;
}
/* 
Popping characters off the front produces: abcdefghij
 */


Get the first element in a vector

 
 
#include <iostream>
using std::cout;
using std::endl;
#include <vector>    // vector class-template definition
#include <algorithm> // copy algorithm
#include <iterator>  // ostream_iterator iterator
#include <stdexcept> // out_of_range exception
int main()
{
   int array[ 6 ] = { 1, 2, 3, 4, 5, 6 };
   std::vector< int > integers( array, array + 6 );
   std::ostream_iterator< int > output( cout, " " );
   integers.push_back( 2 );
   integers.push_back( 3 );
   integers.push_back( 4 );
   cout << "Vector integers contains: ";
   std::copy( integers.begin(), integers.end(), output );
   cout << "\nFirst element of integers: " << integers.front();
   return 0;
}
/* 
Vector integers contains: 1 2 3 4 5 6 2 3 4
First element of integers: 1
 */