vector::begin

Returns a random-access iterator to the first element in the container.

const_iterator begin() const;
iterator begin();

Return Value

A random-access iterator addressing the first element in the vector or to the location succeeding an empty vector. You should always compare the value returned with vector::end to ensure it is valid.

Remarks

If the return value of begin is assigned to a vector::const_iterator, the vector object cannot be modified. If the return value of begin is assigned to an vector::iterator, the vector object can be modified.

Example

// vector_begin.cpp
// compile with: /EHsc
#include <vector>
#include <iostream>

int main()
{
    using namespace std;
    vector<int> c1;
    vector<int>::iterator c1_Iter;
    vector<int>::const_iterator c1_cIter;

    c1.push_back(1);
    c1.push_back(2);

    cout << "The vector c1 contains elements:";
    c1_Iter = c1.begin();
    for (; c1_Iter != c1.end(); c1_Iter++)
    {
        cout << " " << *c1_Iter;
    }
    cout << endl;

    cout << "The vector c1 now contains elements:";
    c1_Iter = c1.begin();
    *c1_Iter = 20;
    for (; c1_Iter != c1.end(); c1_Iter++)
    {
        cout << " " << *c1_Iter;
    }
    cout << endl;

    // The following line would be an error because iterator is const
    // *c1_cIter = 200;
}

The vector c1 contains elements: 1 2
The vector c1 now contains elements: 20 2

Requirements

Header: <vector>

Namespace: std

See Also

Concepts

vector Class

vector Members

Standard Template Library