How to get a value from a vector of structures?

Question

Programming

struct Point {
    double x_a, y_a, x_b, y_b, x_c, y_c;
  };
std::vector<Point> v;

I have a function that receives a vector
func(vector& v);
This vector consists of point value structures. I need to access the value of x_a in the second structure in the vector, then to the value of x_a in the third structure.
But I have no idea how to get them.
xa = v[1.x_a] doesn't work.

Answer 1

v[1].x_a