Thread: Using Vectors

Anywhere you'd normally use an array.

and also if you don't know the size of a data container...

example

Code:

#include <iostream>
#include <vector>     // a must for vector use
using namespace std;

int main()
{
     vector<int> iVector;   // you have to specify the vector type by a class or a structure
     int answer;
     int temp;

     cout<<"How many numbers do you want to enter? ";
     cin>>answer;

     for(int i=0; i < answer; i++)
    {
          answer--;
          cout<<answer<<" Enter a number: ";     // display how many numbers the user has left to enter
          cin>>temp;
          iVector.push_back(temp);    
// this is magic... the temporary integer is pushed onto the back of the vector...and given a location in that vector, which you can access using iVector[anumber]
     }
return0;
}

i prefer using vectors over arrays any day...
Only thing I hate doin, though, is that to access an object of a vector class (ex. iVector.erase()) you have to create a vector iterator that points to a location in the vector

ex.

Code:

class aClass
{
     public:
          int number;
}

aClass theClass;
vector<aClass> theClassV;
vector<aClass>::iterator theClassVIterator;

for(int i=0;i<=3;i++)
{
     theClass[i].number=i;
     theClassV.push_back(theClass);
}

//                                                          0             1               2
// so now theClassV vector holds {theClass, theClass, theClass}
// at the storage spaces 0, 1, 2
// If i wanted to delete what was at location 1 I would have to do this...

for(i=0;i<=2;i++)
{
     theClassVIterator++;
}

theClassV.erase(theClassVIterator);

this is the only way ive found how to make the iterator the position of the vector you want...there probably is a pro somewhere around here who can be sure...

Um, gL_nEwB, despite the name, theClassVIterator is a vector<aClass>.
Assuming such an element exists, if you wanted to delete the element at 'location 1', you would use:

Code:

theClassV.erase(theClassV.begin() + 1);