public member function
reference front ( );
const_reference front ( ) const;
Access first element
Returns a reference to the first element in the vector container.
Unlike member
vector::begin, which returns an iterator to this same element, this function returns a direct reference.
Parameters
none
Return value
A reference to the first element in the vector.
Member types
reference and
const_reference are the reference types to the elements of the vector container (for the default storage allocation model,
allocator, these are
T& and
const T& respectively).
Example
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
|
// vector::front
#include <iostream>
#include <vector>
using namespace std;
int main ()
{
vector<int> myvector;
myvector.push_back(78);
myvector.push_back(16);
// now front equals 78, and back 16
myvector.front() -= myvector.back();
cout << "myvector.front() is now " << myvector.front() << endl;
return 0;
}
|
Output:
myvector.front() is now 62
|
Complexity
Constant.
See also
- vector::at
- Access element (public member function)
- vector::operator[]
- Access element (public member function)
- vector::back
- Access last element (public member function)