vectors

[danciu]

Hi,
when we have a vector, like below, can we consider always that cout<<*v.end()
will print 0 value? Can we find there some garbage value or not?

  int x{1,2,3,4,5}
  vector<int>v(x, x+5);
  cout<<*v.end();
  vector<int>v1(7);
  cout<<*v1.end();

[coder777]

can we consider always that cout<<*v.end()
will print 0 value?

end() returns [a kind of] pointer beyond the end of the vector. It will lead to undefined behavior to dereference this pointer.

Can we find there some garbage value or not?

Yes.

[gunnerfunner]

Use rbegin(), crbegin() for iterator access to the last element or back() for direct access to the last element of the vector:

#include <iostream>
#include <vector>

int main()
{
    std::vector<int> v{1, 2, 3, 4, 5};
    std::cout << *(v.rbegin()) << "\n";
    std::cout << *(v.crbegin()) << "\n";
    std::cout << v.back() << "\n";
}