Member initialization as others have pointed out.
But it is more important to know the following:
When the arguments are of the type float or other built-in types, there's no clear advantages except that using member initialization rather than assignment (in the body of the constructor) is more idiomatic in C++.
The clear advantage is if the arguments are of user-defined classes, this member initialization would result in calls to copy constructors as opposed to default constructors if done using assignments (in the constructor's body).
