Do I have to clear a C++ vector after declaration?

Question

Assume I declare a vector:

std::vector <int> v;

After this declaration, is it guaranteed that the vector is empty or do I have to explicitly clear/initialize it? Is calling v.clear() after the declaration useless or recommended?

Answer 1

When defining a variable like that, the default constructor is called. In vector's case, the default constructor creates an empty vector with no elements, so no, you don't need to explicitly clear it.