vector::operator

Returns a reference to the vector element at a specified position.

reference operator[](
   size_type Pos
);
const_reference operator[](
   size_typePos
) const;

Parameters

Return Value

If the position specified is greater than or equal to the size of the container, the result is undefined.

Remarks

If the return value of operator[] is assigned to a const_reference, the vector object cannot be modified. If the return value of operator[] is assigned to a reference, the vector object can be modified.

When compiling with _SECURE_SCL 1 (controlled with _ITERATOR_DEBUG_LEVEL), a runtime error will occur if you attempt to access an element outside the bounds of the vector. See Checked Iterators for more information.

Example

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

int main( )
{
   using namespace std;   
   vector <int> v1;

   v1.push_back( 10 );
   v1.push_back( 20 );

   int& i = v1[1];
   cout << "The second integer of v1 is " << i << endl;
}

Output

The second integer of v1 is 20

Requirements

Header: <vector>

Namespace: std

See Also

Reference

vector Class

Standard Template Library