STL vector: resize() and assign()

Question

Having a class members std::vector<double> v and int n, what is the difference between using the following on this vector, which is not initialized:

v.assign(n, 0.0); 

or

v.resize(n, 0.0); 

Answer 1

assign sets the size to n and all element values to 0.0, whereas resize sets the size to n and only new element values to 0.0.

If v is empty beforehand, they're the same, but assign is probably clearer.