Use of the vector container begin () and end () function, front () and back () in C++stl

First, the BEGIN function

Function Prototypes:

Iterator begin ();

Const_iterator begin ();

Function:

Returns an iterator to the starting element in the current vector container.

Second, End Function

Function Prototypes:

Iterator End ();

Const_iterator end ();

Function:

Returns an iterator to the end element in the current vector container.

Three, front function

Function Prototypes:

Reference Front ();

Const_reference Front ();

Function:

Returns a reference to the starting element in the current vector container.

Four, back function

Function Prototypes:

Reference back ();

Const_reference back ();

Function:

Returns a reference to the end element in the current vector container.

Instance:

#include <iostream>
#include < Vector>
using namespace std;
int main ()
{
 vector<char> v1;
 vector<char>::iterator Iter1;
 vector<char>::iterator Iter2;
 v1.push_back (' m ');
 v1.push_back (' n ');
 v1.push_back (' O ');
 v1.push_back (' P ');
 
 cout << "v1.front () =" << V1.front () << Endl;
 cout << "v1.back () =" << v1.back () << Endl;
 
 iter1 = V1.begin ();
 cout << *iter1 << Endl;
 iter2 = V1.end ()-1;//note v1.end () points to the next position of the last element, so access to the last element
                        // The correct operation is: V1.end ()-1;
 cout << *iter2 << Endl;
 return 0;
}

Output Result:
V1.front () = m
V1.back () = P
M
P

Use of the vector container begin () and end () function, front () and back () in C++stl