c++ Initialising 2 different iterators in a for loop [duplicate]

Answer 1

For example

intIter i = intVec.begin();
dubIter j = dubVec.begin();
for (; i != intVec.end(); ++i && ++j)
{
  result += (*i) * (*j);
}

you can declare several var. only of the same type in the for. And are you sure with this part

++i && ++j

? I believe you want to write there

 ++i, ++j

So obviously you must read basics about for loop in C++