Code from quiz i do not understand this code how to find its output as it reserve 3 then capacity should be 3 only?

#1

Predict the output :

int main()

{ vector v(3);

for(int i=0;i<7;i=i+2) {

v.push_back(i);

}

cout<<v.capacity(); }

#2

It’s dynamic .
Size doubles when there is shortage.