HELP! Accessing pointer elements of a vector1

[Oz_joker]

Hi!

I’m having trouble knowing how to directly access pointer elements of a vector!

I have declared a vector named “_stationaryVerticeList”. I have declared this vector so that each element of this vector points to a vector of floats…..
-----------------------------------------------------------------------------------

typedef vector<float> VerticeList;    //A vector of Vertice Lists 
                                                           type  def
vector<VerticeList*> _stationaryVerticeList; //A vector of Vertices 
                                                                         for this stationary   
                                                                          object

------------------------------------------------------------------------------------

Now, in turn, I have made 4 float vectors (each with 3 values pushed onto them), and added/pushed them onto the _stationaryVerticeList vector……

VerticeList* NewVerticeList_0 = new VerticeList();
NewVerticeList_0->push_back(45.5);
NewVerticeList_0->push_back(33.2);
NewVerticeList_0->push_back(77.8);
_stationaryVerticeList.push_back(NewVerticeList_0);

VerticeList* NewVerticeList_1 = new VerticeList();
NewVerticeList_1->push_back(23.7);
NewVerticeList_1->push_back(81.5);
NewVerticeList_1->push_back(67.2);
_stationaryVerticeList.push_back(NewVerticeList_1);

VerticeList* NewVerticeList_2 = new VerticeList();
NewVerticeList_2->push_back(54.2);
NewVerticeList_2->push_back(91.2);
NewVerticeList_2->push_back(12.9);
_stationaryVerticeList.push_back(NewVerticeList_2);

VerticeList* NewVerticeList_3 = new VerticeList();
NewVerticeList_3->push_back(14.2);
NewVerticeList_3->push_back(61.8);
NewVerticeList_3->push_back(19.9);
_stationaryVerticeList.push_back(NewVerticeList_3);

------------------------------------------------------------------------------

Now, I need to know how I can directly access one of these vertice values through the _stationaryVerticeList vector! For example, let’s say that I wanted to access the second value from the third list added to the _stationaryVerticeList vector (it should equal 91.2) – how would I do this? ANY help would be GREATLY appreciated!!!!!!

//---------Side Note! -----//
I know the data is being read in properly, because I’ve looped though the _stationaryVerticeList vector using …

for(vector<VerticeList*>::iterator it1 = _stationaryVerticeList.begin(); it1 != _stationaryVerticeList.end(); it1++)
{
  for(vector<GLfloat>::iterator it2 = (*it1)->begin(); it2 != (*it1)->end(); it2++)
  {
     cout << "*It2 is " << (*it2) << endl;
   }
}

…But I need to know how to directly access the values without having to go through this elaborate looping process!

//------End of side note! -------//

[Codeplug]

>> I wanted to access the second value from the third list...
One of a few ways: _stationaryVerticeList[2]->at(1)

gg

[7stud]

“_stationaryVerticeList”. I have declared this vector so that each element of this vector points to a vector of floats…..

That would mean:

_stationaryVerticeList[0]
_stationaryVerticeList[1]
_stationaryVerticeList[2]
_stationaryVerticeList[3]

are all pointers to float vectors. So,

*__stationaryVerticeList[2]

is a float vector. And, you can access the elements of a vector using array notation:

(*_stationaryVerticeList[2])[1]

I don't know the precedence rules for * and [], so I added parentheses.

[CornedBee]

Don't forget that [] is slightly faster than at(), because it doesn't do bounds checking. [] will be undefined on an invalid index, at() will throw.