some different between array and Vector(C++) when trying to swap two element

   Swap two number is most common function used in program,  it is very easy to write the following function:

1. by reference

    void swap (int a, int b)

    {

             int   temp = a;   a = b;  b = temp;

   }

2. by value

   void swap(int &a, int &b)

   {

         int temp = a;  a = b; b = temp; 

    } 

   But when you try to swap two elements of an arrray, function 2 can do this thing, but it can't work when you try to swap two element of a vector:

    like following code:

swap(a[0], a[1]);

printArray(a, (

vector<

swap(ivec[0], ivec[1]);

printVector(ivec);

you will find int a[] is success, but vector<int> ivec is failed. what is the problem?

int a[] = {12, 33, 122, 54, 2, 44, 98}; sizeof (a) / sizeof ( int ) - 1)); int > ivec(a, a + 7);