C++: STL vector<>::front/begin() and vector<>::back/end() methods.

// vector::front - Returns reference to first element of vector.
// vector::back - Returns reference to last element of vector.
// vector::push_back - Appends (inserts) an element to the end of a
//                     vector, allocating memory for it if necessary.
// vector::size - Returns number of elements in the vector.
// vector::begin - Returns an iterator to start traversal of the vector.
// vector::end - Returns an iterator for the last element of the vector.
// vector::erase - Deletes elements from a vector (single & range).

vector<int> vec;

// Intialize the array to contain the members [100, 200, 300, 400]
 for (int i=0; i<4; i++)
        vec.push_back((i + 1) * 100);

cout << "First element: " << vec.front() << endl;
cout << "Last element: " << vec.back() << endl;
cout << "Elements in vector: " << vec.size() << endl;

// Delete the last element of the vector. Remember that the vector
// is 0-based, so theVector.end() actually points 1 element beyond the end.
vec.erase(vec.end() - 1);

cout << endl << "After erasing last element, new last element is: " << vec.back() << endl;

// Delete the first element of the vector.
vec.erase(vec.begin());

cout << "After erasing first element, new first element is: "
     << vec.front() << endl;

cout << "Elements in vector: " << vec.size() << endl;

// Insert an element (number -11) in front of the vector.
vec.insert(vec.begin(),-11);

link: Visual C++ Developer Center / vector::front and vector::back